Installation Instructions
Original Instructions
PowerFlex DC Field Controller Overvoltage Protection Device
Catalog Numbers 23P-FCOVPD-B-FA, 23P-FCOVPD-B-FB, 23P-FCOVPD-D-FA, 23P-FCOVPD-D-FB, 23P-FC-RB100, 23P-FC-RB200, 23P-FC-RB300, 23P-FC-RB400,
23P-FC-RB500
The overvoltage protection device (voltage clamp) helps to provide protection against overvoltage for the PowerFlex® DC field controller when
used with a highly inductive load. An overvoltage can occur when the AC supply voltage is turned off before the field controller is disabled. The
resulting overvoltage can damage the field controller.
The voltage clamp (cat. no. 23P-FCOVPD-
x
-F
x
) is composed of a pair of Silicon Controlled Rectifier (SCR) modules and a circuit board. The
circuit board detects the load voltage level. When a potentially damaging voltage level is detected, the voltage clamp activates the appropriate SCR,
based on the direct of current flow. The SCRs conduct the excess current and allow the resistance in the motor field to gradually decay. The voltage
clamp must not be used to discharge inductive loads routinely. The voltage clamp requires approximately 30 minutes to dissipate the energy from an
overvoltage condition before power can be reapplied to the device.
A dampening resistor (RB) must be installed in combination with the voltage clamp. The dampening resistor is required to dampen the overvoltage
that results from undershooting holding current when the voltage clamp SCR stops conduction. Dampening resistor kits (cat. no. 23P-FC-RB
n
00)
must be purchased separately. See Dampening Resistor on page
3
for details.
The voltage clamp enclosure is rated IP20 and the power terminals are rated IP00. The dampening resistor terminals are rated IP00. Therefore,
these devices must be enclosed in a protective enclosure or appropriate guards must be provided to help protect against an electric shock and/or
burn hazard.
Topic
Page
Product Advisories
2
Required Tools and Hardware
2
System Wiring Diagram
2
Dampening Resistor
3
Optional External Discharge Resistor
3
Voltage Clamp Thermostat
4
Voltage Clamp Nameplate Data
4
Product Dimensions and Weights
5
Minimum Mounting Clearances
8
Install the Voltage Clamp and Dampening Resistor
9
Additional Resources
11
