Section 400. Pumping equipment

A. Proper location. Where practicable, the electric switchgear and motor control centers should be housed above grade and in a separate area from the dry well. All motors and control enclosures shall be adequately protected from moisture from the weather and water under pressure. In cases where equipment may be damaged by flooding from natural events, in such a manner as to cause excessive delays in restoring the pump station to design operating levels, the means of protecting or removing such equipment prior to flooding should be described in the Operation and Maintenance Manual. Motors located indoors and near liquid handling piping or equipment shall be, at least, of-splash-resistant design. Means for heating motors located outdoors or in areas where condensation may occur should be provided. On-site emergency power generation equipment shall be located above grade and be adequately ventilated. Fuel shall be stored in safe locations and in containers specifically designed for fuel storage.

B. Electrical protection. All electrical equipment design (motors, controls, switches, conduit systems, etc.) located in raw sewage wet wells or in totally or partially enclosed spaces where hazardous concentrations of flammable liquids, gases, vapors, or dusts may be present will be evaluated in accordance with the appropriate requirements of the National Electrical Code (e.g., Class I, Group D, Division I for ignitable gases or vapors, etc.) and VOSH requirements.

1. Three-phase motors and their starters shall be protected from electric overload and short circuits on all three phases.

2. All motors shall have a low voltage protection device which, on the reduction or failure of voltage, will cause and maintain the interruption of power to that motor. The low voltage protection device should protect each phase of 3-phase motors.

3. Consideration should be given to the installation of temperature detectors in the stator and bearings of larger motors in order to give an indication of overheating problems.

4. Wires in underground conduits or in conduits that may be flooded shall have moisture resistant insulation as identified in the National Electrical Code.

5. Concrete, metals, control and operating equipment, and safety devices shall, insofar as practical, be designed to protect against corrosion.

6. Electrical power devices or equipment used to convert single phase power to three phase power shall be dedicated to a single specific motor.

C. Testing. Provisions shall be included in the design of equipment requiring periodic testing, to enable the tests to be accomplished while maintaining electric power to all vital components. This requires being able to conduct tests such as actuating and resetting automatic transfer switches and starting and loading emergency generating equipment. The electric distribution system and equipment shall be designed to facilitate inspection and maintenance of individual items without interruption of operations.

D. Generator. The power capacity provided by the on-site emergency generator shall be in accordance with the reliability classification of the pump station. The automatic start system shall be completely independent of the normal electric power source. Air-starting systems shall have an accumulator tank or tanks with a volume sufficient to furnish air for starting the generator engine a minimum of three times without recharging. Batteries used for starting shall have a sufficient charge to permit starting the generator engine a minimum of three times without recharging. The starting system shall be appropriately alarmed and instrumented to indicate loss of readiness (e.g., loss of charge on batteries, loss of pressure in air accumulators, etc.)

E. The specifications shall require that the equipment manufacturers provide to the owner one complete set of operational instructions, equipment and maintenance manuals, with troubleshooting and emergency procedures for each major mechanical and electrical equipment item. The manuals shall contain drawings of equipment and a numbered parts list keyed to a list of components. Tools and such spare parts as may be needed shall also be specified.

Historical Notes

Former 12VAC5-581-460 derived from Volume 18, Issue 10, eff. February 27, 2002; amended and adopted as 9VAC25-790-400, Virginia Register Volume 20, Issue 09, eff. February 12, 2004.

Statutory Authority

§ 62.1-44.19 of the Code of Virginia.