Appendix H NA UL Sub-pump Relay Information
To comply with new UL requirements, newer technology solid state relays are used on the dis-
penser connection board instead of the electro-mechanical type relays.
At new production dispenser installations, the submersible pump relays must comply with the
following specifications:
Submersible Pump Control Relay Specifications:
A UL Listed magnetic motor controller assembly constructed with Potter and Brumfield Relay
No. PRD7AYO (120) or equivalent, shall be used. If an equivalent is used, it must have a minimum
turn on voltage of 102VAC and release voltage no lower than 12VAC for 120VAC applications
or a minimum turn on voltage of 204VAC and release voltage no lower than 24VAC for 240VAC
applications.”
Solid state relays could have a “bleed current” of up to 1.5mA for 120VAC applications and
1.9mA for 240VAC applications. This bleed current on the dispenser’s relay control signals may
cause a logical device such as a power interruption system to misinterpret the control signals.
A bleed resistor may be needed across each relay control signal input to the logical device in
order to maintain the intended communication and not allow the sub-pump to be on when it
should be off. See Warnings below.
A bleed resistor would typically be 10k ohm and 3W for 120VAC applications or 10W for 240VAC
applications; however, it is important that you consult the manufacturer of such devices described
above for information on how to properly load their system to prevent false-positive communica-
tions from the solid state bleed current.
WARNING!
Bleed Resistors
If installing bleed resistors, be aware that they will
produce heat when the submersible pump control is
on; therefore, select the location for the resistors
carefully in order to avoid the risk of fire or personal
injury.
WM048523 Rev 08 01/2019 359
H NA UL Sub-pump Relay Information
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