SECT-48_PUMP_STATION_ELECTRICAL_POWER_&_CONTROL_SYSTEM.DOC

SECTION 48 - PUMP STATION ELECTRICAL POWER AND CONTROL SYSTEM

SECTION 48 - PUMP STATION ELECTRICAL POWER AND CONTROL SYSTEM

Item No. Title

48.9 EMERGENCY POWER RECEPTACLE

48.1 GENERAL

This section specifies the electrical power and control system requirements for wastewater pump stations. These requirements apply to duplex pump panels. Similar requirements shall apply when more than two pumps are involved except for the quantity of control equipment and panel size shall be increased accordingly. The manufacturer of the control panel shall provide data to indicate that the manufacturer has a minimum of three (3) years experience in the building of pump control panels.

A pump station control panel shall be provided for each wastewater pump station. Control panels shall be manufactured by Sta-Con, Inc; Quality Control, Inc.; or approved equal. The control panel shall respond to liquid level float switches to automatically start and stop pumps as well as sound an alarm upon high or low wet well levels. The control panel shall operate two (2) electrical submersible pumps at the power characteristics stipulated. The control function shall provide for the operation of the lead pump under normal conditions. If the incoming flow exceeds the pumping capacity of the lead pump, the lag pump shall automatically start to handle this increased flow. As the flow decreases, pumps shall be cut off at elevation as shown on the PLANS. Pumps shall alternate positions as lead pump at the end of each cycle. A failure of the alternator shall not disable the pumping system. The alternator shall include a safe, convenient method of manual alternation and also have provisions to prevent automatic alternation without disturbing any wiring.

The control panel shall consist of main circuit breakers and generator breaker with mechanical interlock, an emergency power receptacle, a circuit breaker and magnetic starter for each pump motor, and 15 ampere, 120 volt circuit breakers as required. All pump control operations shall be accomplished by a float type liquid level control system with all control components mounted in one common enclosure. Control switches shall provide means to operate each pump manually or automatically. When operated in the automatic mode, the control assembly shall provide means to manually select or automatically alternate the position of the "lead" and "lag" pumps after each pumping cycle. A float type liquid level control system shall continuously monitor wet well liquid level and control operation of the low-level cutoff for the pumps and shall operate off a 24 volt circuit.

48.2 PANEL CONSTRUCTION

The duplex pump panel shall be housed in a NEMA 4X, Type 304, 14 Gauge stainless steel enclosure with 30% extra mounting space for additional equipment. Enclosure shall have provisions for padlocking the door and a dead front inner door unit for mounting controls. All exterior hardware and hinges shall be stainless steel.

There shall be permanently affixed to the interior side of the exterior enclosure door both a nameplate and a 10" x 12" pocket for log sheet storage. The nameplate shall contain the following information, voltage, phase, rated horsepower, speed, date manufactured and pump and control panel manufacturer's name, address, and telephone number, pump data, including impeller data, operating point and head, KW input, and amps at the operating point and at least two other points on the pump curve.

The control panel enclosure shall be Underwriters Laboratories (UL) 50 type 4X listed.

48.3 POWER SUPPLY AND MAIN DISCONNECT

Power supply to the control panel shall be either 208 volt, 3 phase, 4 wire or 480 volt, 3 phase, 4 wire. Minimum service shall be 100 AMP. Single-phase power shall not be accepted.

Nonfusible safety service main disconnects shall be installed at all stations. In all 208 volt systems, disconnects should be installed between the meter and the panel and on all 480 volt systems, disconnect should be installed ahead of the meter. LED power available indicators shall be supplied on all legs.

48.4 CIRCUIT BREAKERS

48.4.1 MAIN BREAKERS

The panel shall have an inter-lock system between the normal power main breaker and the emergency breaker to ensure only one breaker is in the "on" position at a time. Both breakers shall be equal in size. Main breakers shall be manufactured by Westinghouse, Square D or approved equal.

48.4.2 CIRCUIT BREAKERS

All circuit breakers shall be heavy-duty molded case breakers. The handle on the circuit breakers shall be operational through the inner door. Circuit breakers shall be manufactured by Westinghouse, Square D or approved equal.

48.5 MOTOR CIRCUIT PROTECTORS

Each pump motor shall be protected by a 3-pole motor circuit protector. Motor circuit protectors shall be manufactured by Westinghouse, Square D or approved equal. The Motor Circuit Protector shall be operated by a toggle-type handle and shall have a quick-make, quick-break over center switching mechanism that is mechanically trip-free from the handle so that the contacts cannot be held closed against a short circuit and abnormal currents which cause the Motor Circuit Protector to trip. Tripping shall be clearly indicated by the handle automatically assuming a position midway between the normal ON and OFF positions. All latch surfaces shall be ground and polished. All poles shall be so constructed that they open, close, and trip simultaneously. Motor Circuit Protector must be completely enclosed in a high-strength glass polyester molded case. Ampere ratings shall be clearly visible. Contacts shall be of non-welding silver alloy. Arc extinction must be accomplished by means of arc chutes.

48.6 MOTOR STARTER AND SELECTOR SWITCHES

The panel shall contain two motor starters. The motor starter shall be across the line magnetic starter with individual overload protection on each power leg with reset installed through the inner door unit. Motor starters shall be manufactured by Westinghouse, Square D or approved equal. Local power company regulations shall govern.

Selector switches shall be installed on the face of the inner door unit. Selector switch shall be a heavy-duty oil tight "Hand-Off-Auto" three position switch to control the operation mode of each pump motor starter.

48.7 PUMP ALTERNATOR

An eight pin plug-in solid state alternator shall be provided to change the pump starting sequence on each pumping cycle. Pump alternators shall be manufactured by MPC, Diversified or approved equal. A three position alternator test switch shall be provided to control the alternation operation. Switch positions to include the "Auto" to provide normal automatic sequence, "Off" position to disable alternator, and "test" position with a spring return to allow the alternating of the pump sequence to check alternator operation.

48.8 LIGHTS AND ALARMS

48.8.1 INDICATOR LIGHTS

There shall be installed on the face of the inner door unit, heavy-duty oil tight indicator lights as shown on the STANDARD DRAWINGS.

48.8.2 HIGH LEVEL ALARM

A vapor proof red light and horn shall be mounted on top of the panel for high-level alarm. Also, there shall be an alarm silence push-button on the exterior of the panel, which will silence the horn and automatically reset when these signals are restored to normal. The push-button shall be heavy-duty oil tight. The red globe shall be the screw-on type.

48.9 EMERGENCY POWER RECEPTACLE

This item shall only be required on stations that do not have a permanent standby generator system. The panel shall have an external mounted generator receptacle of the required size. Emergency power receptacles shall be manufactured by Russell Stoll #JRSB1044FR.

48.10 ADDITIONAL REQUIREMENTS

48.10.1 WIRING

All power wires shall be THHN, THW or THWN 75 Degree C insulated stranded copper conductors and shall be appropriately sized for the given load application. All control circuit wire shall be type THW; Size 14, stranded type. All wiring within the enclosure shall be neatly routed by the use of slotted type wiring duct with snap on type covers. Wiring on the rear of the inner door shall be neatly bundled with nylon ties and include sufficient loop across the hinges to prevent wire damage, with each end of conductor marked (I.D.), Color: Red, 24 volt; white, neutral; black, 120 volts.

48.10.1A JUNCTION BOX

A junction box shall be installed in the electrical conduit between the wet well and the control panel. The junction box shall be exterior rated for this type of installation. All wires shall go through the junction box and sufficient wire left in the junction box for future use. Sealoffs shall be installed between the junction box and the control panel. Sealoffs may be installed between the junction box and the wet well in accordance with regulations.

48.10.2 TERMINAL POINTS

Terminal points of all terminal strips shall be permanently identified. All terminal numbers and identifying nomenclature shall correspond to and be shown on electrical diagrams. All wiring shall be permanently shown on electrical schematic diagrams.

48.10.3 ENGRAVED NAMEPLATES

All circuit breakers, control switches, indicator pilot lights and other control devices shall be identified with permanently affixed legend plates and lamicoid-type engraved nameplates where applicable.

48.10.4 SURGE PROTECTOR

A surge protector shall be included and wired to protect motors and control equipment from lighting induced line surges. All surge protectors shall be U.L. approved and installed per respective power company requirements and manufacturers' specifications, surge protectors shall be attached to the main disconnects.

48.10.5 ELAPSED TIME METERS

Elapsed time meters shall be 115 volt non-reset type and shall totalize pump running time in hours and tenths of hours to 99999.9 hours.

48.10.6 CONVENIENCE RECEPTACLE

On the face of the inner door unit, there shall be installed a 15 AMP 120 volt, duplex convenience receptacle. It shall be provided with it's own single pole, 15 AMP circuit breaker for protection. Ground fault interrupt type shall be required.

48.10.7 CONTROL TERMINAL BLOCKS

Control terminal blocks shall be of the clamp screw type, rated for 600 volts. Amperage rating shall accommodate the control circuit amperage. An additional 30 space terminal strip shall be installed in the cabinet for future use, with RTU equipment.

48.10.8 CONTROL POWER TRANSFORMERS

There shall be a control power transformer with a minimum size of 2000VA to provide 120VAC power for: coils for starters, 15A duplex receptacle, indicator pilot lights, alarm horn, alarm light, pump alternator, elapsed time meters, etc. The secondary side shall have one leg fused and the other grounded. This control power transformer is required only on 480 volt control panels.

The signal required by the float switches and relays shall be 24VAC. This shall be provided by a 24VAC control power transformer properly sized with a fused secondary.

48.10.9 CONTROL RELAY

The level control relays shall operate from 24VAC. They shall be enclosed, plug-in 8 pin type with octal-style screw terminal sockets.

48.10.10 ELECTRICAL SCHEMATIC

There shall be permanently affixed to the interior side of the exterior enclosure door an electrical schematic diagram and a copy supply to CITY personnel at start-up. The schematic diagram shall include the rated amperage and voltage for all components. The door schematic shall be laminated for preservation and legibility.

48.10.11 PHASE MONITOR

For all 208 through 480 volt stations, an eight pin plug-in type phase monitor shall be provided for protection of electrical components due to phase loss. Adequate dummy pin protection shall be provided to prevent accidental interchanging of the eight pin phase monitor with the eight pin alternator.

48.11 TESTING, SERVICE AND WARRANTY

48.11.1 TESTING

After fabrication in the control panel manufacturer's plant, an operational test shall be performed to check out the entire panel before delivery. Three phase source voltage to which the panel is intended for shall be used for the testing.

48.11.2 SERVICE

The control panel manufacturer shall maintain a service organization in Osceola County that is available for service.

48.11.3 WARRANTY

The manufacturer shall furnish a five (5) year warranty against defects in materials and workmanship covering parts and labor on all items supplied under this section.

48.12 PERIMETER FENCING

Pumping stations shall have a six (6) foot high security type chain link fence around their perimeters, where necessary, as determined by the City Manager’s designated Engineer.

1. MATERIALS

The fabric, posts, fastenings, fittings and other accessories for chain link fence shall meet the requirements of AASHTO M 181 with the following changes:

The base metal of the fabric shall be a good commercial quality 9 gage steel wire. The fabric shall be of uniform quality with a 2-inch mesh size.

All posts and rails shall be in accordance with the following schedule:

End, corner and pull posts – 2 3/8” O.D., Schedule 40.

Line posts and gate frames – 2” O.D., Schedule 40.

Gate posts – 3” O.D., Schedule 40.

Post braces and top rail – 1 5/8” O.D., Schedule 20.

Tension wire shall be 0.177 inch coiled spring wire tensioned along the bottom of the fabric and shall be coated similarly to the wire fabric.

Miscellaneous fittings and hardware shall be zinc coated commercial quality or better steel. Post caps, designed to provide a drive fit over the top of the tubular post to exclude moisture, shall be provided.

1. INSTALLATION

All posts shall be set three (3) feet deep in 12” diameter concrete footings. After the post has been set, aligned and plumbed, the hole shall be filled with 2500 psi concrete. The concrete shall be thoroughly worked into the hole so as to leave no voids. The exposed surface of the concrete shall be crowned to shed water. End, corner, pull and gate posts shall be braced to the nearest post with horizontal brace used as a compression member and a galvanized 3/8 inch steel truss rod and truss tightener used as a tension member. Corner posts and corner bracing shall be constructed at all changes of fence alignment of 30 degrees or more. All chain link fences shall be constructed with a top rail and bottom tension wire.

Swing gates shall be a minimum of two 6-foot wide double hung gates and hinged to swing through 180 degrees from closed to open and shall be complete with latches, locking device, stops keeper, hinges, fabric and braces. Locking device shall be a vertical sliding tube with attached latch. Latch alone with a rod gate holder will not be accepted. Gates shall be the same height as the fence and the gate fabric shall be the same as the fence fabric. Gate leaves less than 8 feet wide shall have truss rods or intermediates braces and gate leaves 8 feet or more in width shall have intermediate braces and diagonal truss rods or shall have a tubular members as necessary to provide rigid construction, free from sad or twist.

The fabric shall not be placed until the posts have been permanently positioned and concrete foundations have attained adequate strength. The fabric shall be placed by securing one end and applying sufficient tension to remove slack before making permanent attachments at intermediate points. The fabric shall be fastened to all corner, end and pull posts by substantial and approved means. Mechanical fence stretchers shall apply stretching.

48.13 REQUIRED SUBMITTALS

Submittals shall be provided to the City in triplicate and include the following:

A. Shop and erection drawings showing all important details of construction, dimensions and anchor bolt locations.

B. Descriptive literature, bulletins, and/or catalogs of the equipment.

E. A drawing showing the layout of the pump control panel shall be furnished. The layout shall indicate all devices mounted on the door and in the panel shall be completely identified.

F. The weight of each pump.

48.14 ELECTRICAL GROUNDING SYSTEMS

A. General A grounding system shall be installed as per National Electrical Code, Local Codes and Ordinances. The DRAWINGS shall clearly show the Electrical Grounding System. An underground perimeter cable grounding system shall be installed with connections to at least the following equipment:

B. Material and Installation The drawings shall show details of material and installation to construct a completely functional and operational Electrical Grounding System.

48.15 INSPECTIONS AND TESTING

A. General Testing of pumping stations shall be done prior to acceptance of the project, which it services. Testing shall be witnessed by representatives of the City Manager’s designated Engineer, project engineer, project contractor, and the lift station manufacturer.

A factory representative knowledgeable in pump operation and maintenance shall inspect and supervise a test run at the pumping station covered by this manual. A minimum of one (1) working day shall be provided for the inspections. Additional time made necessary by faulty or incomplete work or equipment malfunctions shall be provided as necessary to meet the requirements in this manual at no additional cost to the City. Upon satisfactory completion of the test run, the factory representative shall issue the required manufacturer's certificate.

The test run shall demonstrate that all items of this Manual have been met by the equipment as installed and shall include, but not be limited to, the following tests:

1. That all units have been properly installed.

2. That the units operate without overheating or overloading any parts and without objectionable vibration.

3. That there are no mechanical defects in any of the parts.

4. That the pumps can deliver the specified pressure and quantity.

5. That the pumps are capable of pumping the specified material.

6. That the pump controls perform satisfactorily.

B. Pumping Capacity Pumping capacity, by means of on-site pump down testing, shall be proven in the field after installation of pumping station. The designing engineer shall submit a letter stating testing results.