23_09_93,_Sequences_of_Operation_for_HVAC_Control,_20180703.pdf

Repai r Supply building 25 DPEZ022002 (Rev 20180703)

SECTI ON 23 09 93

SEQUENCES OF OPERATI ON FOR HVAC CONTROL

11/15

PART 1 GENERAL

1. 1 DEFINITIONS

For def i ni t i ons r el at ed t o t hi s Sect i on, see Sect i on 23 09 00

I NTRUMENTATI ON AND CONTROL FOR HVAC.

1. 2 SUBMITTALS

Submi t t al s r el at ed t o t hi s Sect i on ar e speci f i ed i n Sect i on 23 09 00

I NTRUMENTATI ON AND CONTROL FOR HVAC.

PART 2 PRODUCTS

Pr oduct s r el at ed t o t hi s Sect i on ar e speci f i ed i n Sect i on 23 09 00 I NTRUMENTATI ON AND CONTROL FOR HVAC and r el at ed Sect i on 23 09 23. 02 BACNET

DI RECT DI GI TAL CONTROL FOR HVAC AND OTHER BUI LDI NG CONTROL SYSTEMS.

PART 3 EXECUTI ON

3. 1 SEQUENCES OF OPERATI ON FOR OCCUPANCY SCHEDULI NG

3. 1. 1 Syst em Mode

Oper at e ai r handl i ng uni t s ( AHUs) i n Occupi ed, War m- Up- Cool - Down, or Unoccupi ed modes as speci f i ed. VAV boxes, Fan Coi l s, and oper at e ot her t er mi nal equi pment i n Occupi ed or Unoccupi ed modes as speci f i ed. Chi l l er s, boi l er s, and ot her sour ces of heat i ng/ cool i ng f or hydr oni c l oads do not r equi r e schedul i ng; t hese syst ems r ecei ve r equest s f or heat i ng/ cool i ng f r om t hei r l oads.

3. 1. 2 Syst em Schedul er Requi r ement s

The Syst em Schedul er f unct i onal i t y must r esi de i n ei t her a pi ece of DDC Har dwar e dedi cat ed t o t hi s f unct i onal i t y or i n t he DDC Har dwar e cont r ol l i ng t he syst em AHU. A s i ngl e pi ece of DDC Har dwar e dedi cat ed t o schedul i ng ( per f or mi ng no ot her cont r ol f unct i onal i t y) may cont ai n mul t i pl e Syst em Schedul er s. Pr ovi de a uni que Syst em Schedul er f or : each AHU i ncl udi ng i t ' s associ at ed Ter mi nal Uni t s, and each st and- al one Ter mi nal Uni t ( t hose not dependent upon AHU ser vi ce) or gr oup of st and- al one Ter mi nal Uni t s act i ng accor di ng t o a common schedul e. Each Syst em Schedul er must pr ovi de t he f ol l owi ng f unct i onal i t y :

3. 1. 2. 1 Schedul ed Occupancy I nput

Accept net wor k var i abl e of t ype SNVT_occupancy. Suppor t t he f ol l owi ng possi bl e val ues: OC_STANDBY, OC_OCCUPI ED and OC_UNOCCUPI ED.

3. 1. 2. 2 Occupancy Over r i de I nput

Accept net wor k var i abl e of t ype SNVT_occupancy. Suppor t t he f ol l owi ng possi bl e val ues: OC_STANDBY, OC_OCCUPI ED, OC_UNOCCUPI ED, and OC_NUL.

SECTI ON 23 09 93 Page 1

Repai r Suppl y Bui l di ng 25 DPEZ022002

3. 1. 2. 3 Space Occupancy I nput s

For syst ems wi t h mul t i pl e occupancy sensor s, accept mul t i pl e i nput s of net wor k var i abl e t ype SNVT_Occupancy. Suppor t t he f ol l owi ng possi bl e val ues: OC_OCCUPI ED, OC_UNOCCUPI ED, and OC_NUL. For syst ems wi t h a s i ngl e occupancy sensor , accept a net wor k var i abl e i nput of t ype SNVT_Occupancy or a har dwar e bi nar y i nput ( BI ) i ndi cat i ng t he space occupancy st at us as Occupi ed or Unoccupi ed.

3. 1. 2. 4 Ai r Handl er Occupancy Out put

For a Syst em Schedul er f or a syst em cont ai ni ng an ai r handl er , out put one or mor e SNVTs i ndi cat i ng t he desi r ed occupancy st at us as one of t he f ol l owi ng possi bl e val ues: War m- Up- Cool - Down ( when r equi r ed by t he AHU Sequence of Oper at i on) , Occupi ed and Unoccupi ed.

3. 1. 2. 5 Ter mi nal Uni t Occupancy Out put

For a Syst em Schedul er f or a st and- al one t er mi nal uni t , or a gr oup of t er mi nal uni t s ser ved by a s i ngl e ai r handl er , out put one or mor e SNVTs i ndi cat i ng t he desi r ed occupancy st at us as one of t he f ol l owi ng possi bl e val ues: Occupi ed and Unoccupi ed.

3. 1. 2. 6 Def aul t Schedul e

I ncor por at e a 24- hour 7- day def aul t schedul e as shown on t he dr awi ngs whi ch may be act i vat ed and deact i vat ed by t he Syst em Schedul er Logi c.

3. 1. 2. 7 Communi cat i on Det er mi nat i on

Det er mi ne t he t i me el apsed bet ween r ecei pt s of t he schedul ed occupancy i nput SNVT, and use t hi s el apsed t i me t o act i vat e and deact i vat e t he Def aul t Schedul e as speci f i ed. ( Thi s pr ovi des t he capabi l i t y f or t he syst em schedul er t o use i t s Def aul t Schedul e i f i t l oses communi cat i on wi t h t he UMCS) .

3. 1. 3 Syst em Schedul er Out put Det er mi nat i on

For cont r ol l i ng an Ai r Handl er , i nt er pr et a SNVT i nput of OC_STANDBY as War m- Up- Cool - Down i f t he sequence of oper at i on suppor t s t hat mode, ot her wi se i nt er pr et OC_STANDBY as Occupi ed. For Ter mi nal Uni t s, i nt er pr et OC_STANDBY as Occupi ed.

3. 1. 3. 1 Ai r Handl er Occupancy Out put

I f mor e t han 95 mi nut es have passed si nce t he l ast r ecei pt of t he Schedul ed Occupancy i nput , det er mi ne t he Ai r Handl er Occupancy Out put by t he def aul t schedul e and t he Space Occupancy I nput s. Ot her wi se, det er mi ne t he out put as f ol l ows:

a. I f t he Over r i de Occupancy I nput i s not OC_NUL, det er mi ne t he Ai r Handl er Occupancy Out put f r om t he Over r i de Occupancy I nput .

b. Ot her wi se, i f at l east t he r equi r ed number ( as shown on t he Occupancy Schedul e Dr awi ng) of Space Occupancy I nput s ar e OC_OCCUPI ED or t he har dwar e BI i s Occupi ed t he Ai r Handl er Occupancy Out put must be

OC_OCCUPIED.

SECTI ON 23 09 93 Page 2

c. Ot her wi se, det er mi ne t he Ai r Handl er Occupancy Out put f r om t he Schedul ed Occupancy I nput SNVT.

3. 1. 3. 2 Ter mi nal Uni t Occupancy Out put

I f mor e t han 95 mi nut es have passed si nce t he l ast r ecei pt of t he Schedul ed Occupancy i nput , det er mi ne t he Ter mi nal Uni t Occupancy Out put by t he def aul t schedul e. Ot her wi se, det er mi ne t he out put as f ol l ows:

a. I f t he Over r i de Occupancy I nput i s not OC_NUL, det er mi ne t he Ter mi nal Uni t Occupancy Out put f r om t he Over r i de Occupancy I nput SNVT:

b. Ot her wi se, det er mi ne t he Ter mi nal Uni t Occupancy Out put f r om t he Schedul ed Occupancy SNVT.

3. 1. 4 Ai r Handl er Syst em Schedul i ng

a. Bi nd t he AHU Occupancy Out put SNVT f r om t he Syst em Schedul er t o t he DDC Har dwar e t hat execut es t he Occupancy Mode Det er mi nat i on par t of t he Ai r Handl er Sequence of Oper at i on

b. For Ai r Handl er s usi ng occupancy sensor s, bi nd t he out put SNVT ( of t ype SNVT_Occupancy) of each occupancy sensor t o a Space Occupancy I nput of t he Syst em Schedul er .

c. Bi nd t he Ter mi nal Uni t Occupancy Out put SNVT f r om t he Syst em Schedul er t o each AHU- Dependent Ter mi nal Uni t .

d. AHU- Dependent Ter mi nal Uni t s wi t h occupancy sensor s must have t he Ef f ect i ve Occupancy SNVT ( of t ype SNVT_Occupancy) of each Ter mi nal Uni t bound t o a Space Occupancy I nput of t he Syst em Schedul er .

3. 1. 5 St and- Al one Ter mi nal Uni t Schedul i ng

Bi nd t he Ter mi nal Uni t Occupancy Out put f r om t he Syst em Schedul er t o t he DDC Har dwar e t hat execut es t he Occupancy Mode Det er mi nat i on par t of t he Ter mi nal Uni t Sequence of Oper at i on.

3. 2 SEQUENCES OF OPERATI ON FOR AI R HANDLI NG UNI TS

3. 2. 1 Heat i ng and Vent i l at i ng Uni t ( or Uni t Vent i l at or )

I nst al l DDC har dwar e t o per f or m t hi s Sequence of Oper at i on and t o pr ovi de SNVT i nput s and out put s as speci f i ed and shown on t he Poi nt s Schedul e.

Unl ess ot her wi se speci f i ed, al l modul at i ng cont r ol must be pr opor t i onal - i nt egr al ( PI ) cont r ol .

3. 2. 1. 1 HAND- OFF- AUTO Swi t ches

Suppl y f an mot or st ar t er must accept a Fi r e Al ar m Panel ( FAP) s i gnal t hat t akes pr ecedence over al l ot her st ar t er i nput s and swi t ches and st ar t t he f an. The f an mot or st ar t er must accept an occupant accessi bl e emer gency shut of f swi t ch as i ndi cat ed. The suppl y f an mot or st ar t er must have an H- O- A swi t ch:

3. 2. 1. 1. 1 HAND

Wi t h t he H- O- A swi t ch i n HAND posi t i on, t he suppl y f an st ar t s and r uns cont i nuousl y, subj ect t o Saf et i es.

SECTI ON 23 09 93 Page 3

3. 2. 1. 1. 2 OFF

Wi t h t he H- O- A swi t ch i n OFF posi t i on, t he suppl y f an st ops.

3. 2. 1. 1. 3 AUTO

Wi t h t he H- O- A swi t ch i n AUTO posi t i on, t he suppl y f an r uns subj ect t o t he Suppl y Fan St ar t / St op ( SF- SS) command and Saf et i es.

3. 2. 1. 2 Occupancy Modes

Obt ai n t he syst em' s Occupancy Mode i nput f r om t he Syst em Schedul er as speci f i ed and i ndi cat ed. Oper at e t he syst em i n one of t he f ol l owi ng modes:

3. 2. 1. 2. 1 Occupied

The Uni t ' s DDC Har dwar e must be i n t he Occupi ed Mode when t he i nput f r om t he Syst em Schedul er ( SYS- OCC) i s occupi ed or when t he l ocal space occupancy i nput ( s) ( ZN- OCC) i ndi cat e t hat t he space i s occupi ed.

3. 2. 1. 2. 2 Unoccupied

The Uni t ' s DDC Har dwar e must be i n t he Unoccupi ed Mode when t he i nput f r om t he Syst em Schedul er ( SYS- OCC) i s unoccupi ed and when t he l ocal space occupancy i nput ( s) ( ZN- OCC) i ndi cat e t hat t he space i s unoccupi ed.

3. 2. 1. 3 Syst em Enabl e and Loop Enabl e

3. 2. 1. 3. 1 Occupi ed Mode

Enabe t he suppl y f an ( SYS- ENA) and command t o r un ( SF- SS) . Enabl e t he Zone Temper at ur e Cont r ol l oop and Mi xed Ai r Damper Cont r ol .

3. 2. 1. 3. 2 Unoccupi ed Mode

Di sabl e al l cont r ol l oops. When BLDG- T dr ops bel ow BLDG- T- LL- SP ( wi t h a 5 degr ees F deadband) enabl e t he suppl y f an ( SYS- ENA) and command t o r un ( SF- SS) and enabl e t he Zone Temper at ur e Cont r ol l oop.

3. 2. 1. 4 Pr oof s and Saf et i es

Subj ect t he suppl y f an and al l DDC Har dwar e cont r ol l oops t o Pr oof s and Saf et i es. Di r ect - har dwi r e i nt er l ock saf et i es t o t he f an st ar t er c i r cui t as i ndi cat ed. DDC Har dwar e must moni t or al l pr oof s and saf et i es and f ai l ur e of any pr oof or act i vat i on of any saf et y must r esul t i n al l cont r ol l oops bei ng di sabl ed and t he AHU f an bei ng commanded of f unt i l r eset .

3. 2. 1. 4. 1 Proofs

Suppl y f an st at us ( pr oof ) ( SF- S)

3. 2. 1. 4. 2 Safeties

a. Heat i ng Coi l di schar ge ai r t emper at ur e l ow l i mi t ( f r eeze st at )

(HTG-DA-T-LL)

b. Suppl y ai r smoke ( SA- SMK)

SECTI ON 23 09 93 Page 4

c. Ret ur n ai r smoke ( RA- SMK)

3. 2. 1. 4. 3 DDC Har dwar e

DDC Har dwar e r eset al l pr oof s and saf et i es v i a a l ocal bi nar y push- but t on ( RST- BUT) i nput t o t he DDC Har dwar e, v i a a r emot e command t o t he DDC Har dwar e v i a SNVT or bot h ( wher e t he Cont r act or pr ovi des bot h r eset f unct i ons and t he oper at or can use ei t her one t o per f or m t he r eset ) , as i ndi cat ed on t he Poi nt s Schedul e dr awi ng.

3. 2. 1. 5 Zone Temper at ur e Cont r ol

3. 2. 1. 5. 1 Enabl ed Loop

When t hi s l oop i s enabl ed, t he DDC Har dwar e must modul at e t he heat i ng val ve and out s i de ai r , r el i ef , and r et ur n ai r damper s i n sequence t o mai nt ai n zone t emper at ur e ( ZN- T) at set poi nt ( ZN- T- SP) . Pr ovi de sequenci ng as i ndi cat ed: Upon a r i se i n zone t emper at ur e above zone t emper at ur e set poi nt ( ZN- T- SP) , subj ect t o t he zone t emper at ur e set poi nt deadband as i ndi cat ed, mocul at e t he out s i de ai r , r el i ef , and r et ur n ai r damper s t o mai nt ai n zone t emper at ur e at set poi nt . Dur i ng occupi ed mode, out s i de ai r damper mi ni mum posi t i on ( OA- D- MI N) shal l be as i ndi cat ed. Upon a f al l i n zone t emper at ur e bel ow zone t emper at ur e set poi nt , subj ect t o t he deadband as i ndi cat ed, modul at e t he heat i ng val ve t owar ds open t o mai nt ai n zone t emper at ur e setpoint.

3. 2. 1. 5. 2 Di sabl ed Loop

When t hi s l oop i s di sabl ed, c l ose t he heat i ng val ve and cl ose t he out s i de ai r damper and r el i ef damper and open t he r et ur n damper .

3. 2. 2 Var i abl e Ai r Vol ume Syst em wi t hout Ret ur n Fan

I nst al l DDC har dwar e t o per f or m t hi s Sequence of Oper at i on and t o pr ovi de SNVT i nput s and out put s as speci f i ed and shown on t he Poi nt s Schedul e.

Unl ess ot her wi se speci f i ed, al l modul at i ng cont r ol shal l be pr opor t i onal - i nt egr al ( PI ) cont r ol .

3. 2. 2. 1 HAND- OFF- AUTO Swi t ches

Suppl y f an var i abl e f r equency dr i ve ( VFD) uni t shal l accept a Fi r e Al ar m Panel ( FAP) s i gnal t hat t akes pr ecedence over al l ot her VFD i nput s and swi t ches and shal l cause t he VFD t o r un at 100 per cent speed. The VFD shal l accept an occupant accessi bl e emer gency shut of f swi t ch as shown. The suppl y f an var i abl e f r equency dr i ve ( VFD) uni t shal l have an i nt egr al H- O- A switch:

3. 2. 2. 1. 1 HAND

Wi t h t he H- O- A swi t ch i n HAND posi t i on, t he suppl y f an shal l s t ar t and r un cont i nuousl y, subj ect t o Saf et i es. Fan speed shal l be under manual - oper at or control.

3. 2. 2. 1. 2 OFF

Wi t h t he H- O- A swi t ch i n OFF posi t i on, t he suppl y f an shal l s t op.

SECTI ON 23 09 93 Page 5

3. 2. 2. 1. 3 AUTO

Wi t h t he H- O- A swi t ch i n AUTO posi t i on, t he suppl y f an shal l r un subj ect t o t he Suppl y Fan St ar t / St op Si gnal ( SF- SS) and Saf et i es. Fan speed shal l be under cont r ol of t he DDC Har dwar e.

3. 2. 2. 2 Occupancy Modes

The syst em shal l obt ai n i t s Occupancy Mode i nput f r om t he Syst em Schedul er as speci f i ed and shown. The syst em shal l oper at e i n one of t he f ol l owi ng modes: Occupi ed, Unoccupi ed, or War m Up/ Cool Down.

3. 2. 2. 3 Pr oof s and Saf et i es

The suppl y f an, r et ur n f an, and al l DDC Har dwar e cont r ol l oops shal l be subj ect t o Pr oof s and Saf et i es. Saf et i es shal l be di r ect - har dwi r e i nt er l ocked t o t he VFD as shown. DDC Har dwar e shal l moni t or al l pr oof s and saf et i es and f ai l ur e of any pr oof or act i vat i on of any saf et y shal l r esul t i n al l cont r ol l oops bei ng di sabl ed and t he AHU f an bei ng commanded of f unt i l r eset .

3. 2. 2. 3. 1 Proofs

a. Suppl y f an st at us ( SF- S)

3. 2. 2. 3. 2 Safeties

a. Pr eheat coi l di schar ge ai r t emper at ur e l ow l i mi t ( f r eezest at ) ( PH- DA- T- LL) f or syst ems wi t h a pr eheat coi l . Cool i ng coi l di schar ge ai r t emper at ur e l ow l i mi t ( f r eezest at ) ( CLG- DA- T- LL) f or al l ot her systems

b. Suppl y ai r duct pr essur e hi gh l i mi t ( SA- P- HL)

c. Suppl y ai r smoke ( SA- SMK)

3. 2. 2. 3. 3 DDC Har dwar e Reset

DDC Har dwar e r eset of al l pr oof s and saf et i es shal l be v i a a l ocal bi nar y push- but t on ( RST- BUT) i nput t o t he DDC Har dwar e, v i a a r emot e command t o t he DDC Har dwar e v i a SNVT or bot h ( wher e t he Cont r act or pr ovi des bot h r eset f unct i ons and t he oper at or can use ei t her one t o per f or m t he r eset ) , as shown on t he Poi nt s Schedul e dr awi ng.

3. 2. 2. 4 Syst em Enabl e and Loop Enabl e

3. 2. 2. 4. 1 Occupi ed Mode

The suppl y f an shal l be enabl ed ( SYS- ENA) and commanded t o r un ( SF- SS) .

Al l cont r ol l oops shal l be enabl ed.

3. 2. 2. 4. 2 Unoccupi ed Mode

Whi l e t he bui l di ng t emper at ur e ( BLDG- T) i s above t he l ow l i mi t set poi nt ( BLDG- T- LL) al l cont r ol l oops shal l be di sabl ed and t he suppl y f an shal l not r un. When BLDG- T dr ops bel ow BLDG- T- LL ( wi t h a 5 degr ees F deadband) t he suppl y f an shal l be enabl ed ( SYS- ENA) and commanded t o r un ( SF- SS) , t he

SECTI ON 23 09 93 Page 6

Suppl y Duct St at i c Pr essur e Cont r ol , Pr eheat Cont r ol l oops shal l be enabl ed. The Mi ni mum Out si de Ai r Fl ow Cont r ol , Mi xed Ai r Temper at ur e Cont r ol , and Cool i ng Coi l Cont r ol l oops shal l be di sabl ed.

3. 2. 2. 4. 3 War m Up/ Cool Down

The suppl y f an shal l be enabl ed ( SYS- ENA) and commanded t o r un ( SF- SS) .

The Mi ni mum Out s i de Ai r Fl ow Cont r ol l oop shal l be di sabl ed and al l ot her cont r ol l oops shal l be enabl ed.

3. 2. 2. 5 Fan Capaci t y Cont r ol

3. 2. 2. 5. 1 Suppl y Duct St at i c Pr essur e Cont r ol

When t hi s l oop i s enabl ed t he DDC Har dwar e shal l modul at e t he suppl y f an var i abl e f r equency dr i ve uni t t o mai nt ai n t he duct st at i c pr essur e ( SA- P) at set poi nt ( SA- P- SP) as shown, as measur ed by t he duct st at i c pr essur e t ap and sensor as shown. When t hi s l oop i s di sabl ed, t he DDC Har dwar e capaci t y modul at i on out put t o t he VFD shal l be zer o per cent .

3. 2. 2. 6 Mi ni mum Out si de Ai r Fl ow Cont r ol

When t hi s l oop i s enabl ed t he DDC Har dwar e shal l modul at e t he mi ni mum out si de ai r damper t o mai nt ai n t he mi ni mum OA vol umet r i c f l ow ( MI NOA- F) at set poi nt ( MI NOA- F- SP) as shown. When t hi s l oop i s di sabl ed, t he mi ni mum out si de ai r damper shal l be c l osed.

3. 2. 2. 7 Mi xed Ai r Temper at ur e Cont r ol Wi t h Economi zer

3. 2. 2. 7. 1 Enabl ed Loop

When t hi s l oop i s enabl ed, and t he Economi zer i s ON as det er mi ned by t he Economi zer Enabl e Logi c, t he DDC Har dwar e shal l modul at e t he economi zer out s i de ai r , r el i ef , and r et ur n ai r damper s t o mai nt ai n t he mi xed ai r t emper at ur e ( MA- T) at set poi nt ( MA- T- SP) as shown.

3. 2. 2. 7. 2 Di sabl ed Loop

When t hi s l oop i s di sabl ed, or t he Economi zer i s OFF as det er mi ned by t he Economi zer Enabl e Logi c, t he economi zer out s i de ai r and r el i ef ai r damper s shal l be c l osed, and t he r et ur n ai r damper shal l be open.

3. 2. 2. 7. 3 Economi zer Enabl e Logi c

The economi zer shal l be ON when t he out s i de ai r dr y bul b t emper at ur e i s bet ween t he hi gh l i mi t ( ECO- HL- SP) and l ow l i mi t ( ECO- LL- SP) set poi nt s as shown. The Economi zer shal l ot her wi se be OFF. ECO- HL- SP and ECO- LL- SP shal l each have a 2 degr ees F deadband.

3. 2. 2. 8 Cool i ng Coi l Cont r ol

When t hi s l oop i s enabl ed t he DDC Har dwar e shal l modul at e t he cool i ng coi l val ve t o mai nt ai n t he suppl y ai r t emper at ur e ( SA- T) set poi nt ( SA- T- SP) as shown. When t hi s l oop i s di sabl ed, t he cool i ng coi l val ve shal l be c l osed.

3. 2. 2. 9 Pr eheat Coi l Cont r ol

When t hi s l oop i s enabl ed t he DDC Har dwar e shal l modul at e t he pr eheat coi l val ve t o mai nt ai n t he pr eheat coi l di schar ge ai r t emper at ur e ( PH- DA- T) at

SECTI ON 23 09 93 Page 7 set poi nt ( PH- DA- T- SP) as shown. When t hi s l oop i s di sabl ed, t he pr eheat coi l val ve shal l be c l osed.

3. 3 SEQUENCES OF OPERATI ON FOR TERMI NAL UNI TS

3. 3. 1 Zone Temper at ur e Cont r ol - Cool i ng- Onl y VAV Box

I nst al l DDC har dwar e t o per f or m t hi s Sequence of Oper at i on and t o pr ovi de SNVT i nput s and out put s as speci f i ed and shown on t he Poi nt s Schedul e.

Unl ess ot her wi se speci f i ed, al l modul at i ng cont r ol shal l be pr opor t i onal - i nt egr al ( PI ) cont r ol .

3. 3. 1. 1 Occupancy Modes

3. 3. 1. 1. 1 Occupied

The VAV box DDC Har dwar e shal l be i n t he Occupi ed Mode when t he l ocal space occupancy i nput ( s) ( ZN- OCC) i ndi cat e t hat t he space i s occupi ed or when t he i nput f r om t he Syst em Schedul er ( SYS- OCC) i s occupi ed.

3. 3. 1. 1. 2 Unoccupied

The VAV box DDC Har dwar e must be i n t he Unoccupi ed Mode when t he l ocal space occupancy i nput ( s) ( ZN- OCC) i ndi cat e t hat t he space i s unoccupi ed and t he i nput f r om t he Syst em Schedul er ( SYS- OCC) i s unoccupi ed.

Safeties

Thi s syst em has no saf et i es.

3. 3. 1. 2 Zone Temper at ur e Cont r ol

3. 3. 1. 2. 1 Occupi ed Mode

I n t he Occupi ed Mode t he zone t emper at ur e set poi nt ( ZN- T- SP) must be at t he conf i gur ed set poi nt or at t he occupant - adj ust abl e set poi nt v i a t he wal l - mount ed t her most at , as shown. The DDC Har dwar e must modul at e t he VAV box damper t o mai nt ai n VAV box suppl y ai r f l ow ( VAV- SA- F) at set poi nt as measur ed by a mul t i - poi nt f l ow sensi ng el ement at t he i nl et t o t he VAV box. Sequenceas i ndi cat ed: Upon a r i se i n zone t emper at ur e ( ZN- T) above zone set poi nt ( ZN- T- SP) , subj ect t o t he zone t emper at ur e set poi nt deadband as i ndi cat ed, adj ust t he ai r f l ow set poi nt bet ween mi ni mum and maxi mum f l ow based on t he di f f er ence bet ween zone t emper at ur e and zone t emper at ur e set poi nt as i ndi cat ed.

3. 3. 1. 2. 2 Unoccupi ed Mode

I n t he Unoccupi ed Mode t he VAV box damper shal l be at i t s mi ni mum posi t i on.

3. 3. 2 Zone Temper at ur e Cont r ol - VAV Box wi t h Reheat

I nst al l DDC har dwar e t o per f or m t hi s Sequence of Oper at i on and t o pr ovi de SNVT i nput s and out put s as speci f i ed and shown on t he Poi nt s Schedul e.

Unl ess ot her wi se speci f i ed, al l modul at i ng cont r ol shal l be pr opor t i onal - i nt egr al ( PI ) cont r ol .

SECTI ON 23 09 93 Page 8

3. 3. 2. 1 Occupancy Modes

3. 3. 2. 1. 1 Occupied

The VAV box DDC Har dwar e shal l be i n t he Occupi ed Mode when t he l ocal space occupancy i nput ( s) ( ZN- OCC) i ndi cat e t hat t he space i s occupi ed or when t he i nput f r om t he Syst em Schedul er ( SYS- OCC) i s occupi ed.

3. 3. 2. 1. 2 Unoccupied

The VAV box DDC Har dwar e shal l be i n t he Unoccupi ed Mode when t he l ocal space occupancy i nput ( s) ( ZN- OCC) i ndi cat e t hat t he space i s unoccupi ed and t he i nput f r om t he Syst em Schedul er ( SYS- OCC) i s unoccupi ed.

3. 3. 2. 2 Safeties

VAV boxes wi t h el ect r i c r esi st ance heat i ng el ement s shal l r equi r e pr oof of ai r f l ow bef or e act i vat i ng t he heat i ng el ement s.

3. 3. 2. 3 Zone Temper at ur e Cont r ol

a. I n t he Occupi ed Mode t he zone t emper at ur e set poi nt ( ZN- T- SP) shal l be at t he conf i gur ed set poi nt or at t he occupant - adj ust abl e set poi nt v i a t he wal l - mount ed t her most at , as shown.

b. I n t he Unoccupi ed Mode t he zone t emper at ur e set poi nt ( ZN- T- SP) shal l be at t he conf i gur ed set poi nt as shown.

c. The DDC Har dwar e shal l modul at e t he VAV box damper t o mai nt ai n VAV box suppl y ai r f l ow ( VAV- SA- F) at set poi nt as measur ed by a mul t i - poi nt f l ow sensi ng el ement at t he i nl et t o t he VAV box. Sequenci ng shal l be as shown: Upon a r i se i n zone t emper at ur e above zone t emper at ur e set poi nt ( ZN- T- SP) , subj ect t o t he zone t emper at ur e set poi nt deadband as shown, t he ai r f l ow set poi nt shal l be adj ust ed bet ween mi ni mum and maxi mum f l ow based on t he di f f er ence bet ween zone t emper at ur e and zone t emper at ur e set poi nt as shown. Upon a f al l i n zone t emper at ur e bel ow zone t emper at ur e set poi nt , subj ect t o t he deadband as shown, t he ai r f l ow shal l be mai nt ai ned at a f i xed ai r f l ow set poi nt ( wi t h a set t i ng i ndependent of t he cool i ng mi ni mum ai r f l ow) , and t he heat i ng val ve shal l modul at e t owar ds open or t he st aged el ect r i c r esi st ance heat i ng coi l ( s) shal l cycl e on i n sequence.

3. 3. 3 Uni t Heat er and Cabi net Uni t Heat er

I nst al l DDC har dwar e t o per f or m t hi s Sequence of Oper at i on and t o pr ovi de SNVT i nput s and out put s as speci f i ed and shown on t he Poi nt s Schedul e.

Unl ess ot her wi se speci f i ed, al l modul at i ng cont r ol shal l be pr opor t i onal - i nt egr al ( PI ) cont r ol .

3. 3. 3. 1 Of f - Aut o Swi t ch

3. 3. 3. 1. 1 OFF

Wi t h t he t her most at OFF- AUTO swi t ch i n t he OFF posi t i on, t he DDC Har dwar e shal l s t op t he f an and cl ose t he heat i ng cont r ol val ve.

3. 3. 3. 1. 2 AUTO

Wi t h t he t her most at OFF- AUTO swi t ch i n t he AUTO posi t i on, t he DDC Har dwar e

SECTI ON 23 09 93 Page 9 shal l cont r ol t he uni t i n accor dance wi t h i t s Occupancy Mode.

3. 3. 3. 2 Occupancy Modes

3. 3. 3. 2. 1 Occupied

The uni t heat er DDC Har dwar e shal l be i n t he Occupi ed Mode when t he l ocal space occupancy i nput ( s) i ndi cat e t hat t he space i s occupi ed or when t he i nput f r om t he Syst em Schedul er i s occupi ed.

3. 3. 3. 2. 2 Unoccupied

The uni t heat er DDC Har dwar e shal l be i n t he Unoccupi ed Mode when t he l ocal space occupancy i nput ( s) i ndi cat e t hat t he space i s unoccupi ed and when t he i nput f r om t he Syst em Schedul er i s unoccupi ed.

3. 3. 3. 3 Safeties

The uni t shal l r un subj ect t o t he uni t manuf act ur er ' s saf et i es.

3. 3. 3. 4 Space Temper at ur e Cont r ol

3. 3. 3. 4. 1 Occupi ed Mode

I n t he Occupi ed Mode t he DDC Har dwar e shal l modul at e t he heat i ng cont r ol val ve and cycl e t he mul t i - speed f an t o mai nt ai n space t emper at ur e at t he conf i gur ed set poi nt or at t he occupant - adj ust abl e set poi nt v i a t he wal l - mount ed t her most at , as shown.

3. 3. 3. 4. 2 Unoccupi ed Mode

I n t he Unoccupi ed Mode t he DDC Har dwar e shal l modul at e t he heat i ng cont r ol val ve and cycl e t he mul t i - speed f an t o mai nt ai n space t emper at ur e at t he conf i gur ed set poi nt as shown.

3. 3. 4 Gas- Fi r ed I nf r ar ed Heat er

I nst al l DDC har dwar e t o per f or m t hi s Sequence of Oper at i on and t o pr ovi de SNVT i nput s and out put s as speci f i ed and shown on t he Poi nt s Schedul e.

Unl ess ot her wi se speci f i ed, al l modul at i ng cont r ol shal l be pr opor t i onal - i nt egr al ( PI ) cont r ol .

3. 3. 4. 1 On- Of f - Aut o Swi t ch

3. 3. 4. 1. 1 ON

Wi t h t he t her most at ON- OFF- AUTO swi t ch i n t he ON posi t i on, t he DDC Har dwar e shal l ener gi ze t he heat er and t he heat er shal l r un cont i nuousl y.

3. 3. 4. 1. 2 OFF

Wi t h t he t her most at ON- OFF- AUTO swi t ch i n t he OFF posi t i on, t he DDC Har dwar e shal l de- ener gi ze t he heat er .

3. 3. 4. 1. 3 AUTO

Wi t h t he t her most at ON- OFF- AUTO swi t ch i n t he AUTO posi t i on, t he DDC Har dwar e shal l cont r ol t he heat er i n accor dance wi t h i t s Occupancy Mode.

SECTI ON 23 09 93 Page 10

3. 3. 4. 2 Occupancy Modes

3. 3. 4. 2. 1 Occupied

The uni t DDC Har dwar e shal l be i n t he Occupi ed Mode when t he l ocal space occupancy i nput ( s) i ndi cat e t hat t he space i s occupi ed.

3. 3. 4. 2. 2 Unoccupied

The uni t DDC Har dwar e shal l be i n t he Unoccupi ed Mode when t he l ocal space occupancy i nput ( s) i ndi cat e t hat t he space i s unoccupi ed.

3. 3. 4. 3 Safeties

The heat er shal l r un subj ect t o t he uni t manuf act ur er ' s saf et i es.

3. 3. 4. 4 Space Temper at ur e Cont r ol

3. 3. 4. 4. 1 Occupi ed Mode

I n t he Occupi ed Mode t he DDC Har dwar e shal l oper at e t he heat er t o mai nt ai n space t emper at ur e at t he conf i gur ed set poi nt or at t he occupant - adj ust abl e set poi nt v i a t he wal l - mount ed t her most at , as i ndi cat ed.

3. 3. 4. 4. 2 Unoccupi ed Mode

I n t he Unoccupi ed Mode t he DDC Har dwar e shal l oper at e t he heat er t o mai nt ai n space set poi nt at t he conf i gur ed unoccupi ed set poi nt as i ndi cat ed.

3. 4 SEQUENCES OF OPERATI ON FOR HYDRONI C SYSTEMS

3. 4. 1 Hydr oni c Heat i ng Hot Wat er Fr om Bui l di ng Boi l er s

I nst al l DDC har dwar e t o per f or m t hi s Sequence of Oper at i on and t o pr ovi de SNVT i nput s and out put s as speci f i ed and shown on t he Poi nt s Schedul e.

Unl ess ot her wi se speci f i ed, al l modul at i ng cont r ol shal l be pr opor t i onal - i nt egr al ( PI ) cont r ol .

3. 4. 1. 1 Syst em Enabl e and Loop Enabl e

a. Thi s syst em shal l moni t or t he enabl ed st at us of al l syst ems ser ved by t hi s syst em. I f one or mor e syst ems ser ved by t hi s syst em ar e enabl ed, t hi s syst em shal l be enabl ed ( SYS- ENA) . I f no syst ems ser ved by t hi s syst em ar e enabl ed, t hi s syst em shal l be di sabl ed.

b. When t hi s syst em i s enabl ed ( SYS- ENA) and t he hot wat er pump i s pr oof ed on, t he boi l er cont r ol and hot wat er t emper at ur e cont r ol l oops shal l be enabled.

3. 4. 1. 2 HAND- OFF- AUTO Swi t ch

The hot wat er pump mot or st ar t er shal l have an H- O- A swi t ch:

3. 4. 1. 2. 1 HAND

Wi t h t he H- O- A swi t ch i n HAND posi t i on, t he pump shal l s t ar t and r un continuously.

SECTI ON 23 09 93 Page 11

3. 4. 1. 2. 2 OFF

Wi t h t he H- O- A swi t ch i n OFF posi t i on, t he pump shal l s t op.

3. 4. 1. 2. 3 AUTO

Wi t h t he H- O- A swi t ch i n AUTO posi t i on, t he pump shal l r un subj ect t o t he Hot Wat er Pump St ar t / St op ( HW- PMP- SS) command.

3. 4. 1. 3 Pr oof s and Saf et i es

DDC Har dwar e shal l moni t or al l pr oof s and saf et i es.

3. 4. 1. 3. 1 Proofs

Hot wat er pump

3. 4. 1. 3. 2 Safeties

None

3. 4. 1. 3. 3 DDC Har dwar e Reset

DDC Har dwar e r eset of al l pr oof s and saf et i es shal l be v i a a l ocal bi nar y push- but t on ( RST- BUT) i nput t o t he DDC Har dwar e, v i a a r emot e command t o t he DDC Har dwar e v i a SNVT or bot h ( wher e t he Cont r act or pr ovi des bot h r eset f unct i ons and t he oper at or can use ei t her one t o per f or m t he r eset ) , as shown on t he Poi nt s Schedul e dr awi ng.

3. 4. 1. 4 Boi l er Cont r ol

When t hi s l oop i s enabl ed, t he DDC Har dwar e shal l t ur n t he boi l er on. When t hi s l oop i s di sabl ed, t he boi l er shal l be of f .

3. 4. 1. 5 Hot Wat er Temper at ur e Cont r ol

When t hi s l oop i s enabl ed t he DDC Har dwar e shal l modul at e t he 3- way mi xi ng val ve t o mai nt ai n hot wat er suppl y t emper at ur e ( HWS- T) at set poi nt ( HWS- T- SP) . The Hot Wat er Suppl y Temper at ur e Set poi nt ( HWS- T- SP) shal l be as shown. When t hi s l oop i s di sabl ed, t he val ve shal l be i n i t s nor mal ( f ai l saf e) posi t i on.

3. 4. 2 Hydr oni c Secondar y wi t h Var i abl e Speed Pump

I nst al l DDC har dwar e t o per f or m t hi s Sequence of Oper at i on and t o pr ovi de SNVT i nput s and out put s as speci f i ed and shown on t he Poi nt s Schedul e.

Unl ess ot her wi se speci f i ed, al l modul at i ng cont r ol shal l be pr opor t i onal - i nt egr al ( PI ) cont r ol .

3. 4. 2. 1 Syst em Enabl e and Loop Enabl e:

a. Thi s syst em shal l moni t or t he enabl ed st at us of al l syst ems ser ved by t hi s syst em. I f one or mor e syst ems ser ved by t hi s syst em ar e enabl ed, t hi s syst em shal l be enabl ed ( SYS- ENA) . I f al l syst ems ser ved by t hi s syst em ar e not enabl ed, t hi s syst em shal l not be enabl ed.

b. When t hi s syst em i s enabl ed ( SYS- ENA) t he Pr essur e Cont r ol l oop shal l be enabl ed.

SECTI ON 23 09 93 Page 12

3. 4. 2. 2 HAND- OFF- AUTO Swi t ch

The hot wat er pump var i abl e f r equency dr i ve ( VFD) uni t shal l have an i nt egr al H- O- A swi t ch:

3. 4. 2. 2. 1 HAND

Wi t h t he H- O- A swi t ch i n HAND posi t i on, t he pump st ar t s and r uns cont i nuousl y. Pump speed shal l be under manual - oper at or cont r ol .

3. 4. 2. 2. 2 OFF

Wi t h t he H- O- A swi t ch i n OFF posi t i on, t he pump st ops.

3. 4. 2. 2. 3 AUTO

Wi t h t he H- O- A swi t ch i n AUTO posi t i on, t he pump shal l r un subj ect t o t he Hot Wat er Pump St ar t / St op ( HW- PMP- SS) command and pump speed shal l be under cont r ol of t he DDC syst em.

3. 4. 2. 3 Pr oof s and Saf et i es

DDC Har dwar e shal l moni t or al l pr oof s and saf et i es.

3. 4. 2. 3. 1 Proofs

None

3. 4. 2. 3. 2 Safeties

None

3. 4. 2. 3. 3 DDC Har dwar e Reset

DDC Har dwar e r eset of al l pr oof s and saf et i es shal l be v i a a l ocal bi nar y push- but t on ( RST- BUT) i nput t o t he DDC Har dwar e, v i a a r emot e command t o t he DDC Har dwar e v i a SNVT or bot h ( wher e t he Cont r act or pr ovi des bot h r eset f unct i ons and t he oper at or can use ei t her one t o per f or m t he r eset ) , as shown on t he Poi nt s Schedul e dr awi ng.

3. 4. 2. 4 Pr essur e Cont r ol

When t hi s l oop i s enabl ed t he DDC Har dwar e shal l modul at e t he pump var i abl e f r equency dr i ve uni t t o mai nt ai n t he pi pe syst em pr essur e at set poi nt as shown, as measur ed by t he di f f er ent i al pr essur e t ap and sensor as shown.

When t hi s l oop i s di sabl ed, t he DDC Har dwar e capaci t y modul at i on out put t o t he VFD shal l be zer o per cent .

- - End of Sect i on - -

SECTI ON 23 09 93 Page 13

3.4.2.4 Pressure Control