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This article describes How to Find & Use the Water Pump Relay Switch. The page top photo shows a typical wall-mounted Goulds (TM) relay switch used to power a submersible well pump. Readers of this document should also see Water pump and pressure tank repair diagnosis & cost an specific case which offers an example of diagnosis of loss of water pressure, loss of water, and analyzes the actual repair cost.

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How to Locate & Use the Water Pump Relay Switch

How to Recognize and Locate a Pump Relay Switch In this photograph a pump relay switch is mounted on the wall to the left of the blue water pressure tank. You'll notice that an electrical conduit can be seen running down the wall below this gray switch box. The relay is usually mounted on a wall near the water pressure tank. How are Water Pump Relay Switches Wired & Controlled? Electrical power, either 120V or 240V, is brought into the relay switch from the electrical panel and is connected to one side of an internal relay switch inside the box. Wiring to the water pump, usually a submersible pump located inside the well, is connected to the other side of the relay switch. A separate pair of wires will run from the relay switch to the pump pressure control switch. (See that little gray box at the lower end of the conduit below the larger, wall-mounted gray pressure switch box?). When the pump pressure control switch detects that the water pump should turn on, a light-duty switch inside of the water pump pressure control switch senses this pressure drop and turns on the heavy-duty electrical relay switch inside of the wall mounted pump relay. The wall mounted relay thus is sending power to the water pump.

When do we use a pump relay switch

A pump relay switch such as the relay switches shown in photographs in this article is used to power a water pump when the voltage/amperage combination would be too much to switch on and off by the simple pump pressure switch.

It is possible to power smaller horsepower (lower amperage-drawing) submersible pump directly from the pump pressure control switch. While you'll see even some submersible pumps wired this way (that is the wall mounted heavy duty relay switch is not provided), larger horsepower submersible well pumps draw sufficient amperage that if they were wired through a little pressure control switch at the water tank that switch would burn up pretty quickly.

When are pump relay switches not used?

Pump relay switches are not installed on every water pump, and are usually not found when the water pump is above ground such as when a one line or two line jet pump is installed at or near the water pressure tank.

Combined Heavy Duty Pump Relays and Pressure Controls Some heavy duty submersible pump relays such as the Homat(TM) switch shown in this photograph combine the pressure control sensor and the heavy duty pump electrical relay switch. Notice the copper tube entering the pump relay box at the lower right in this photo? Also notice that this switch has a pressure gauge right on the switch box face. This pump control switch has combined a water pressure sensor and switch with the relay to send power to the water pump. So inspecting the rest of the water equipment at this building we won't expect to find that ordinary little gray box which controls pump operation on a lower horsepower water pump.

Where is the "electrical ON-OFF switch" when a wall mounted heavy duty pump relay is installed?

We may not see a separate wall mounted electrical switch by the pump controls when a heavy duty relay such as those discussed here is installed. Rather, on at least some of these switches, pulling off the cover of the relay box will actually disconnect internal components and thus serves as a local electrical switch for the water pump.

Safety warning live voltage is inside of all of these pump switches - and is a shock hazard. When you don't see an ordinary wall switch to turn off the water pump you're probably safer going to the electrical panel where you can turn off power to the water pump by switching off the appropriate circuit breaker or pulling the appropriate fuse.

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PLUMBING TOPICS
OIL TANKS
SEPTIC SYSTEMS
WATER PRESSURE REGULATOR ADJUST
WATER PRESSURE REPAIR GUIDE & COSTS
WATER PRESSURE LOSS DIAGNOSIS GUIDE
WATER PRESSURE & FLOW MEASUREMENT
WATER PUMPS & WELL TANKS
WATER PUMP CONTROLS & SWITCHES
  IDENTIFY WELL PUMP TANK COMPONENTS
  MAIN WATER SHUTOFF VALVE
  WATER PUMP ELECTRICAL SWITCHES
  WATER PUMP PRESSURE CONTROL
    WATER PUMP PRESSURE CONTROL ADJUSTMENT
    WATER PUMP PRESSURE CONTROL REPAIR
    WATER PUMP PRESSURE CONTROL REPLACE
  WATER PRESSURE REGULATOR ADJUST
  WATER PUMP RELAY SWITCH
  WATER TANK AIR VOLUME CONTROLS
  TANK AIR INLET VALVE
  TANK AIR VALVE REPAIRS
  WATER TANK PRESSURE GAUGE
  WATER TANK DRAIN VALVE
  WATER TANK RELIEF VALVE
  CHECK VALVES
  WATER FILTERS
WATER PUMP TYPES & LIFE EXPECTANCY
WATER PUMP & TANK SAFETY
WATER SUPPLY & DRAIN PIPING
WATER TANK TYPES: WATER, OIL, EXPANSION, ALL
WATER TANK LIFE EXPECTANCY
WATER TANK REPAIRS
WATER TANK AIR, HOW TO ADD
WATER TANK BLADDERS & CAPTIVE AIR
WATER TANK BLADDER PRESSURE ADJUSTMENT
WATER TANK PRESSURE CALCULATIONS
WATER TANK SIZE & VOLUME
WATER TANKS HOW THEY WORK
WATER TESTING
WATER TREATMENT EQUIPMENT CHOICES
WELLS CISTERNS & SPRINGS
WELL, PUMP, TANK LIFE EXPECTANCY

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