MECHANICAL AND CONTROL SYSTEMS

Environmental Control System

Building Automation System

VA MEDICAL CENTER

HVAC CONTROLS UPGRADE - PHASE 2A

WILMINGTON, DELAWARE

PROJECT

OWNER

ENGINEER

CONTRACTOR

211-1009IW/BM 3/7/11IW/BMIW

REFERENCE DRAWING

SUB. REVISION TITLE AND DATE REVS.1 4/20/11 BM

NO. REVISION-LOCATION ECN DATE BY

SUB. REVISION REVISION DATES2 5/10/11 BM

SUB. REVISION ADDED DWG. C-3; HX3 8/8/11 BM

Automatic Temperature Controls

Heating

Air Conditioning

Air Filters

Water Treatment

Coil Cleaning

Contract Operations

Time-Shared Automated Building Service

Refrigeration

Industrial Controls / Recording / Indication Equipment

Air and Water Systems Balancing

Instrumentation System Installation

Building Operations Management

Energy Conservation Control

Custom Programmed Maintenance

HATCH MOTT MACDONALD

27 BLEEKER ST.

MILLBURN, NJ 07041

BOB SMITH CONTRACTORS

281 EAST EVERGREEN ST.

WEST GROVE, PA 19390

DEPT. OF VETERANS AFFAIRS

1601 KIRKWOOD HIGHWAY

WILMINGTON, DE 19805

PAGE # DRAWING TITLE LAST REVISION

TP-1 TITLE PAGE 01/28/14

C-1A AIR HANDLING UNIT CONTROL – AHU FOR 4TH FLOOR WEST 12/02/13

C-1B CONTROLLER WIRING DETAIL – AHU FOR 4TH FLOOR WEST 12/02/13

C-1C AHU FOR 4TH FLOOR WEST – SEQUENCE OF OPERATIONS 12/02/13

C-1D AHU FOR 4TH FLOOR WEST – VAV BOX CONTROLS 12/02/13

C-2A AIR HANDLING UNIT CONTROL – AHU FOR 4TH FLOOR EAST 12/02/13

C-2B CONTROLLER WIRING DETAIL – AHU FOR 4TH EAST 12/02/13

C-2C AHU FOR 4TH FLOOR EAST – SEQUENCE OF OPERATIONS 12/02/13

C-2D AHU FOR 4TH FLOOR EAST – VAV BOX CONTROLS 12/02/13

C-3 HEAT EXCHANGER CONTROL; 4TH FLOOR MECH. ROOM 12/02/13

1 2 3

VA HVAC CONTROLS UPGRADE - PHASE 2A

(PARTIAL SUBMITTAL - 4TH FLOOR EAST & WEST HVAC EQUIPMENT) 4

AS-BUILT REV. FINAL AS-BUILT DATES4 12/20/13 BM

NOTE(S): REFER TO ‘MASTER BUILDING NETWORK ARCHITECTURE DRAWING’

PROVIDED IN OUR ATC AS-BUILT / O&M MANUAL BINDER FOR ALL

SUPERVISORY CONTROLLER INFORMATION AND ASSOCIATED IP

ADDRESSES USED BY MODERN CONTROLS.

REFER TO ‘MASTER BUILDING VALVE SCHEDULE’ PROVIDED IN OUR

ATC AS-BUILT / O&M MANUAL BINDER FOR A COMPLETE LIST OF ALL

CONTROL VALVES PROVIDED FOR AIR HANDLING UNITS AND

ASSOCIATED VAV BOXES.

AS-BUILT REV. ADD ‘MASTER’ NOTE5 1/28/14 DB

211-1009

IW/BMIW/BMIW VD 3/7/11

REFERENCE DRAWING

SUB. REVISION REVISE DWG. TITLE1 4/20/11 BM

C-1D

NO. REVISION-LOCATION ECN DATE BY

Sales Engineer Project Manager Application Engineer

BY DATE BY DATE

DRAWN APPROVED

Branch Information CONTRACT NUMBER

RAWING NUMBER

VA HVAC CONTROLS UPGRADE

- PHASE 2A

WILMINGTON, DELAWARE

Drawing Title

AIR HANDLING UNIT;

AHU FOR 4TH FLOOR WEST -

SEQUENCE OF OPERAITONS

Project Title

AIR HANDLING UNIT; AHU FOR 4TH FLOOR WEST - SEQUENCE OF OPERATIONS

GENERAL:

Unit AHU and return fan are normally started and stopped by the DCP (EX.CP) or remotely at the BMS. H-O-A switch shall be kept in the ‘AUTO’ position.

‘HAND’ and ‘OFF’ positions shall be used for maintenance only. When the unit is ‘OFF’ D-1 and D-3 shall be closed. When the unit is ‘ON’ D-1 and D-3 shall be open.

TEMPERATURE CONTROL:

Supply air temperature sensed by T-1 shall be maintained at set point via DCP (EX.CP) by modulating either V-1 and V-2 or D-1, D-2 and D-3 in sequence.

When the temperature of the outside air provided by BMS is above 65 F DCP (EX.CP) prevents modulation of D-1, D-2 and D-3; D-1 assumes minimum outside air position (D-3 is closed and D-2 is open). V-1 modulates to maintain supply air temperature sensed by T-1.

When the temperature of the outside air provided by the BMS is between 65F and the supply air temperature sensed by T-1 damper D-2 is closed. Damper D-1 is open (maximum outside air position) and damper D-3 is open. V-1 modulates to maintain the supply air temperature sensed by T-1.

When the temperature of the outside air provided by the BMS is below the supply air temperature sensed by T-1 then dampers D-1, D-2 and D-3 modulate to maintain the schedules supply air temperature and the pump at the reheat coil runs. If D-2 is open and D-1 is closed to minimum outside air in the mode V-2 modulates open to maintain the supply air temperature.

AIR FLOW CONTROLS:

The supply air flow is controlled by the DCP (EX.CP) modulating supply fan variable speed motor controller (VSMC) to maintain the duct static pressure set point as sensed by SPS-1

The DCP (EX.CP) by using total supply air and return air flow signals shall reset the return air fan VSMC to maintain a constant CFM difference between the supply air fan CFM and the return air fan CFM.

The DCP (EX.CP) by using high pressure sensor SPS-2 located at the supply air fan discharge prevents the supply air fan from developing over 3" static pressure. If static pressure at SPS-2 exceeds 3" the supply fan stops.

HUMIDITY CONTROL:

When the DCP (EX.CP) is not calling for humidification sensed by exhaust air humidistat H-1, the stand alone electric humidifier shall be off. When the DCP (EX.CP) is calling for humidity, the humidifier shall operate under it’s built in controls to maintain desired humidity sensed by H-1.

The BMS shall override the control to maintain humidity in supply duct below 80% as sensed by H-2. BMS shall shut the humidifier off whenever the supply fan is off.

FREEZE PROTECTION:

If the air temperature sensed by T-2 falls below 45F an alarm signal shall indicate at the DCP (EX.CP) and BMS. If the temperature falls below 40F the supply fan shall shut down, damper D-1 shall close and a critical alarm shall indicate at the DCP (EX.CP) and BMS.

EMERGENCY SHUTDOWN/RESTART

When smoke is detected by the duct mounted smoke detector the supply and return fans shall stop and the alarm signal shall be transmitted to the fire alarm system, dampers D-1, D-2, SD-1 and SD-2 shall close, damper D-3 shall open. Supply and return fans shall restart and dampers open when the fire alarm circuit is manually reset.

EMERGENCY CONSTANT SPEED OPERATION

Upon failure of VSMC the supply and return fans shall be started/stopped manually at the DCP (EX.CP) or the BMS through the bypass starter. Fans shall then operate at constant speed.

AS-BUILT REV. NEW DWG. / DATES2 12/2/13 BM