Sequence Of Operation - Bryant SM03-4 Service Manual

DO NOT REMOVE
OPTIONAL
SAFETY
GROUND
DRAIN
HOLE
Fuse Data: 5-amp automotive-type ATC/ATO (tan)
32v
200 percent current opening time of 5 sec maximum
A. Electrical Connections
Eighteen 0.187-in quick-connect terminals are used to provide
programming selections for operating modes of ICM2. The 5
selection modes are listed below. For additional information, refer
to Easy Select Configuration Taps section.
AUX Heat Range—(Violet Wire)
AC/HP Size—(Blue Wire)
Type—(Orange Wire)
AC/HP CFM Adjust—(Black Wire)
AC/HP Time Delay—(Grey Wire)
III. SEQUENCE OF OPERATION
A. Continuous Fan Mode
The thermostat closes circuit R to G. The G signal is sent directly
to ICM2.
B. Cooling Mode—Single Speed or 2-Speed High
Thermostat closes circuits R to Y/Y2 and R to O (heat pump only)
for single speed. A circuit from R to Y1 is also required for
2-speed high. The Y/Y2 signal is sent directly to ICM2.
C. Cooling Mode—Two-Speed Low
Thermostat closes circuits R to Y1 and R to O (heat pump only).
The Y1 signal is sent directly to ICM2.
Fig. 15—FK4B, FK4C and FV4A ICM2 Motor
—21—
OPTIONAL SAFETY GROUND
1 2 3
POWER CONNECTOR
9 10 11 12 13 14 15 16
1 2 3 4 5 6 7 8
CONTROL CONNECTOR
D. Electric Heat Heating Mode
Thermostat closes circuit R to W2, W3, or E.
The terminal block positions W2, W3, and E are tied together by
jumpers JW1 and JW2. These jumpers are provided for field
staging of electric heater banks through use of thermostats. When
staging is a requirement, installer cuts jumpers and wires in
thermostats as is the common practice with other fan coils. To
ensure motor operation if any 1 of the inputs is energized, the 3
electric heater inputs are also interlocked through diodes D1, D2,
and D3 to motor W input.
E. Heat Pump Heating Mode—Single Speed or 2-Speed
High
Thermostat closes circuit R to Y/Y2 for single speed. A circuit
from R to Y1 is also required for 2-speed high. The Y/Y2 signal
is sent directly to ICM2.
F. Heat Pump Heating Mode—Two-Speed Low
Thermostat closes R to Y1. The Y1 signal is sent directly to ICM2.
G. Heat Pump Heating With Auxiliary Electric Heat
Thermostat closes circuits R to Y/Y2 and/or R to Y1 with R to W2,
W3, or E (and R to O in the case of defrost).
See previously described modes for circuit paths.
In the event that electric heating is called for by thermostat while
heat pump is also operating in either heating or defrost mode,
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