Rockwell Automation 1503 IntelliVAC Contactor Control Module - Series C and later - Manual (Page 33)

3-20 Installation and Wiring
1503-UM052D-EN-P – June 2013
Undervoltage Protection The IntelliVAC controller protects the contactor from control voltage
dips and loss of power. It provides undervoltage release and prevents
attempts to close the contactor when there is not sufficient power
available to guarantee reliable closing of the contacts. The undervoltage
protection will be initiated under the following conditions, regardless of
nominal control voltage:
1. If the supply voltage drops below 90 V (AC or DC) during the first
200 milliseconds after a Close command is received. This applies to
both electrically held and mechanical latch contactors.
2.
If the supply voltage drops below 72 V (AC or DC) after the 200
millisecond close sequence (electrically held contactors only).
Time Delay Undervoltage
The IntelliVAC can be configured to provide time delay undervoltage
(TDUV) protection. The feature is available to keep electrically held
contactors closed during a voltage dip or brief power loss. This option
may require the addition of a capacitor (see below). Refer to Chapter 6
for typical capacitor sizing. The capacitor is connected to terminals 1(-)
and 2(+) of the IntelliVAC. (Refer to Figure 3.13.)
A T T E N T I O N A T T E N T I O N
If the TDUV feature is used, the contactor will
not open until the programmed TDUV time
has expired. Therefore, applications requiring
an immediate removal of power during
emergency stop conditions are not compatible
with the TDUV feature.
Table 4.B of the “Setup and Commissioning” chapter has the dip switch
settings to provide TDUV from 0.2 to 2 seconds. IntelliVAC can
provide TDUV protection without the use of an external capacitor, as
shown in Table 3.D.
Table 3.D – Maximum TDUV Time (without Capacitor)
Control Voltage
Max. TDUV Time (secs)
400 A 800 A
110/120 V 0.2 0.2
220/240 V 1.0 1.0
If the undervoltage condition persists beyond the set delay time, the
contactor will be opened and an undervoltage fault or warning condition will
occur (see Chapter 5).