Watlow QPAC - Manual (Page 17)

QPAC User's Guide 17 Chapter 2: Install & Wire
Input Wiring
AL Control Card,Current
Transformer Selection.
Example of Current
Transformer (CT)
Connections One CT, 150
Amps and Above, 1Ø.
CT
AL Card
Bk
Bk
Bk
16-0176
Transformer
Red
Red
Wh
TB-3
TB-2
5A
20mA
5A:20mA
T2 T1
1
5
Load
Soft Start
(Available on the Phase Angle input cards AF and AL only.)
Some heater elements change resistance with temperature. Certain types,
such as tungsten, change resistance very fast (tungsten increases resis-
tance over 16 times from cold to hot). By slowly increasing the voltage to the
heater, the heater element is warmed to full resistance by the time full volt-
age is applied, thus reducing excessive surge currents. Soft start time on the
QPAC is about 6 seconds from power-up. If the QPAC is forced into emer-
gency shut down (ESD) the QPAC will restart soft. Soft start is only available
on phase angle models.
AL Control Card Current Transformer Connections
Phase Angle Current Limit Option
The AL Control Card is wired to a transformer from the load line of the
QPAC. The transformer is wired into pins 1 and 2 of connector TB3 of the AL
card. The following table and figures show the transformer connections for
different load configurations and currents.
Current Transformer
(Part Number)
Description Interstage
Transformer
Not Used 5A : 20mA Interstage Transformer 16-0176
16-0008 150A : 5A Current Transformer 16-0176
16-0045 200A : 5A Current Transformer 16-0176
16-0073 300A : 5A Current Transformer 16-0176
0004-0286-0400 400A : 5A Current Transformer 16-0176
0004-0286-0500 500A : 5A Current Transformer 16-0176
0004-0286-0600 600A : 6A Current Transformer 16-0176
0004-0287-0800 800A : 5A Current Transformer 16-0176
0004-0288-1000 1,000A : 5A Current Transformer 16-0176