Rockwell Automation 1503VC IntelliVAC Contactor Control Module - Manual (Page 27)

Installation and Wiring 3-15
1503-UM051D-EN-P – June 2013
Capacitor Trip
The IntelliVAC can be configured to provide capacitor trip
functionality with mechanically latched contactors. A capacitor must
be connected to the IntelliVAC (terminals #1 and #2) in order to
provide this capability. The capacitor provides control power for the
IntelliVAC as well as stored energy to trip the contactor. Maximum
recommended capacitor size is 1650 µF for 120V control or 330 µF
for 240V control. Use of larger capacitors will require a current
limiting circuit to prevent opening the control fuse on energization.
The IntelliVAC must receive an ‘OPEN’ command within a few
seconds of losing AC control power. This time limit depends on
voltage and capacitor size as shown in the table below. If the
elapsed time exceeds this limit, the contactor cannot be tripped by
IntelliVAC.
A separate voltage source is needed to provide the ‘OPEN’ command.
This may be taken from the external capacitor as shown in Figure
3.13.
Table 3.C – Mechanically Latched Contactor – Capacitor Trip Times
Contactor
Rating
Nominal Voltage
(Vac)
Actual
V
input
(Vac)
Ext.
Capacitor
(µF)
Max. time
for trip
(sec)
120 3.5
110 2.7 120
100
1650
1.7
240 7.5
400 Amp
240
200
330
4.7
Note:
Minimum capacitor voltage ratings
• 120V applications – 200V DC (250V DC preferred)
• 240V applications – 400V DC (450V DC preferred)
Mechanically Latched
Contactors