Watlow QPAC - Manual (Page 4)

4 QPAC User's Guide Chapter 1: Starting Out
Starting Out
The Q32
SCR Power Control.
General Description
The QPAC Power Controls are a family of solid-state controls used for elec-
tric heating applications. A solid-state power control provides output power
that is proportional to the input command signal from a temperature control.
This proportional output power helps to produce a closely controlled heater
temperature, which saves energy and prolongs heater life by holding heater
elements at a nearly constant temperature.
The QPAC has a modular construction with plug-in features for flexibility.
The three modules of the QPAC are the Power Base, Transformer and
Control Card. See the QPAC Modularity Overview below. Power Bases are
available in 150 to 1,000A ratings with UL508 listed and cULus in single-
phase, three-phase two-leg and three-phase three-leg configurations. A
Transformer plugged into the Power Base allows the QPAC to operate
Chapter 1
Starting Out With The QPAC Power
Control