Section 8. Sequence Of Operation - Trane BAYEVAC04BK1B Installer's Manual

INSTALLER'S GUIDE
Section 8. Heater Operation
8.1 TAM7 Heater Operation
Electric Heat
1. R-W contacts close on the comfort control sending
24VAC to W1 of the AFC.
2. R-G contacts close on the comfort control sending
24VAC to G of the AFC.
3. The AFC communicates to the EHC that 1st stage elec-
tric heat is being called upon.
4. The EHC determines the number of elements that are
used for 1st stage and sends a message to the AFC for
that correct cfm. (The EHC determines the amount of
heat per stage by either factory programming or by the
kw jumper position)
5. The AFC micro-processor sends a command to the serial
communicating blower motor to run and close the blower
interlock relay on the EHC. The blower motor will now run
at the W1 electric heat cfm.
6. On subsequent calls for W2 and/or W3, the EHC will
communicate to the AFC the required airflow request
and energize the additional relays.
NOTE: The EHC has "lead-lag" logic built in that energizes
the electric heat relays based upon cycle counts.
For example: BAYEV**15 – The first time W1 only is ener-
gized; the K1 relay would close and energize the "A"
heater. The second time W1 only is energized; the K2
relay would close and energize the "B" heater. The third
time W1 only is energized; the K3 relay would close and
energize the "C" heater.
8.2 TAM8 Heater Operation
Electric Heat
1.
When a request for electric heat is received, the AFC
communicates to the EHC how much demand for auxil-
iary heat is being requested
2. The EHC determines the number of elements that will be
used for this request and sends a message to the AFC
for proper airflow. (The EHC determines the amount of
heat available per stage by either factory programming or
by the kW jumper position)
3. The AFC sends a command to the serial communicating
blower motor to run proper airflow and close the blower
interlock relay on the EHC.
4. As demand from the thermostat increases, the EHC will
communicate to the AFC the required airflow when ener-
gizing additional relays.
NOTE: The EHC has "lead-lag or rotating" logic built in that
energizes the electric heat relays based upon cycle
counts. To verify operation of all heating elements, switch
thermostat to Emergency Heat and raise the setpoint of
the thermostat at least 5 degrees above the actual room
temperature.
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8.3 TAMG Heater Operation
Electric Heat
1. R-W contacts close on the comfort control sending
24VAC to W1 of the AFC.
2. R-G contacts close on the comfort control sending
24VAC to G of the AFC.
3. The AFC communicates to the EHC that 1st stage elec-
tric heat is being called upon.
4. The EHC determines the number of elements that are
used for 1st stage and sends a message to the AFC for
that correct cfm. (The EHC determines the amount of
heat per stage by either factory programming or by the
kw jumper position)
5. The AFC micro-processor sends a command to the
serial communicating blower motor to run and close the
blower interlock relay on the EHC. The blower motor will
now run at the W1 electric heat cfm.
6. On subsequent calls for W2 and/or W3, the EHC will
communicate to the AFC the required airflow request
and energize the additional relays.
NOTE: The EHC has "lead-lag" logic built in that energizes
the electric heat relays based upon cycle counts.
For example: BAYEV**15 – The first time W1 only is ener-
gized; the K1 relay would close and energize the "A"
heater. The second time W1 only is energized; the K2
relay would close and energize the "B" heater. The third
time W1 only is energized; the K3 relay would close and
energize the "C" heater.