Rockwell Automation 1503 IntelliVAC Contactor Control Module - Series C and later - Manual (Page 30)

Installation and Wiring 3-17
1503-UM052D-EN-P – June 2013
Capacitor Trip
The IntelliVAC can be configured to provide capacitor trip functionality
with mechanical latch 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. In this case, the
contactor can be tripped by pressing the release button on the door in
front of the contactor.
A separate voltage source is needed to provide the ‘OPEN’ command. This
may be taken from the external capacitor as shown in Figure 3.11.
Table 3.C – Mechanical Latch Contactor – Capacitor Trip Times
Contactor
Rating
Nominal Voltage
(Vac)
Actual
V
input
(Vac)
Ext. Capacitor
(µF)
Max. time
for trip
(sec)
400 Amp
120
120
1650
3.5
110 2.7
100 1.7
240
240
330
7.5
200 4.7
Note: Minimum capacitor voltage ratings:
• 120V applications – 200V DC (250V DC preferred)
• 240V applications – 400V DC (450V DC preferred)
Mechanical Latch Contactors