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Duplex Electrical Alternator Control Panel

Control Panels

Duplex Electrical Alternator Control Panel

Use these control panels in duplex systems to alternate use of the pumps with each cycle or run both simultaneously in the event of high water levels.

Features and Benefits

An Electrical Alternator is used on a duplex pump application where automatic electrical cycling of the pump is desired for added protection in residential or commercial applications. With one pump operating to handle normal flow, a second pump becomes operational in the event the water level continues to rise. The built-in alarm system, a standard feature, can be connected to sound when the second pump becomes operational (3-float switch system) or independently (4-float switch system).

All electrical systems must be installed by a qualified electrician and according to the National Electrical Code (see section 430-71 through 430-113, plus any others that apply).

Control Panel Features

  • Hand-off-auto toggle switch for each pump
  • Green pump run pilot light for each pump
  • Alarm test and silence switches
  • Red pilot light (NEMA 1 only) and audible alarm with 83 to 85 decibel rating for a high water condition
  • Red alarm beacon included with NEMA 4X enclosure
  • Auxiliary dry contact
  • High water alarm
  • On single phase – circuit breaker for each pump
  • On three phase – motor protective switch with overload protection
  • Magnetic starter for each pump
  • Alternating mechanism
  • Numbered terminal strip for connecting pumps and variable level float switches
  • NEMA 1, general purpose or NEMA 4X, watertight enclosures available
  • Integral auxiliary terminal board connections (dry contact) for remote alarm devices
  • 3 or 4 variable level float switch control operation
  • Three 20’ (6 m) float switches included with 1 Ph panels
  • The use of off-the-shelf components provide for relatively easy field maintenance and repair
  • Float switches not included with three phase panels (see FM0526)
  • Receive alarms through Z Control® Cloud! See FM3010.
  • Refer to FM0712 for correct selection of Electrical Alternator
  • 2 year limited warranty

Sequence of Operation for Duplex Panel

1. Operation can begin after the following:

  • Correct voltage is supplied to the panel
  • Panel is properly grounded
  • Pumps are connected correctly to panel
  • Panel circuit breakers are closed
  • Floats are properly installed
  • Overload protection is adjusted to pump nameplate amps
  • Pump HOA switches are set to ‘Auto’
  • Control on/off switch is set to ‘On’

2. When the ‘Stop’ and ‘Lead’ floats are closed, pump 1 will energize and the pump 1 run light will illuminate. Pump 1 will remain operational until the ‘Stop’ float opens.

3. The next time the ‘Stop’ and ‘Lead’ floats are closed the alternating circuit will energize pump 2 and the pump 2 pump run light will illuminate. Pump 2 will remain operational until the ‘Stop’ float opens. This cycle will repeat each time the fluid level rises and falls.

4. If the fluid level continues to rise after the first pump has been energized, the ‘Lag’ float will close. When the ‘Lag’ float has closed the second pump will energize. Both pumps will remain operational until the ‘Stop’ float opens.

5. In a three-float system when the ‘Lag’ float is closed, the following will also occur:

  • The external high water light will illuminate
  • The audible high water horn will sound
  • The auxiliary dry contacts will close

6. In a four-float system, the alarm float should be the third float causing an alarm to sound when the lead pump fails to operate or the rate of in flow into the basin exceeds the capacity of one pump. When the alarm float is closed the following will occur:

  • The external high water light will illuminate
  • The audible high water alarm will sound
  • The auxiliary dry contacts will close

As the liquid level continues to rise the fourth float will close, energizing the lag pump. The lag pump and the lead pump will remain energized until the "Stop" float opens.
*NOTE: In Duplex systems where it is considered normal for two pumps to operate in tandem during peak flow conditions, the third and fourth float may be reversed.

7. The audible high water horn can be silenced by pressing the alarm silence button. When the ‘Alarm’ float opens the external high water light, audible high water horn and dry auxiliary contacts will be reset.

600 and X600 series single phase pumps require special panels that include start components. See FM0712 for correct panel selection.

All variable level float switches in this section are mechanically activated and do not contain mercury.