Installation Instructions

5
2.5 OVERLOAD PREVENTION CONTROL
BOARD (OPCB)
The OPCB can control an air conditioner (24 VAC) directly or a
separate contactor PPM (24 VAC or 120 VAC operating coil) which
can control any load connected to it. See Figure 2.1.
The Power Management Module (PMM) is not supplied with the
transfer switch. It can be purchased separately from the manufac-
turer for use with the Overload Prevention Control Board (OPCB)
mounted in the transfer switch. The OPCB is designed and con-
nected to power the PMM contactor operating coil. The OPCB is
supplied by a 24 VAC supply, class 2 power supply transformer,
connected to the LOAD supply in the RTS. (Each output is limited
to 1 amp) The PMM contactor coil connections are made at the
OPCB terminal strip.
Connect the PMM contactor coil to OPCB contactor terminals (1,
2, 3 or 4). The selection of contactor terminal used will depend on
the priority of the load being controlled. This is a 24 VAC circuit
and wiring methods for class 2 should be used. Use ¼” quick
connect terminals to make the contactor coil connections on the
PMM. See Figure 2.1.
A grommet is provided to route Class 2 wiring through. The grom-
met can be used in any knockout for NEMA 1 installations. The
grommet can only be used in the bottom knockouts for NEMA 3R
installations.
Control of Air Conditioner Load
1. Route the thermostat cable (from the furnace/thermostat to
the outdoor air conditioner unit) to the transfer switch.
2. Connect the wire to the terminal strip terminals (Air 1) on
the OPCB as shown in Figure 2.1. These are normally closed
contacts which open upon load shed conditions. Route ther-
mostat wire away from High voltage wires.
3. If required, connect the second air conditioner to the terminal
strip terminals (Air 2).
Contact Ratings
Air 1 & 2 24 VAC, 5.0 Amps Max
Installation
Y wire
Y wire
0 Ground
194 +12V
23 Transfer
T1
NEUTRAL
A/C 1
24V
A/C 2
24V
LOAD 1
LOAD 2
LOAD 3
LOAD
4
A/C 1 & LOAD 1
PMM #1 Load #1
Supply
Coil wires
PMM #2 Load #2
Supply
PMM #4 Load #4
Supply
PMM #3 Load #3
Supply
LOAD
SUPPLY
LOAD
SUPPLY
1
2
1
2
2
2
2
1
1
1
1A MAX
1A MAX
1A MAX
1A MAX
A/C 2 & LOAD 2
LOAD 3
LOAD 4
Figure 2.1 — Overload Prevention Control