Evaporator Heater Contactor Control; Remote Start/Stop Volt-Free Contact; Remote Volt-Free Contact For Cooling Temperature Setpoint Selection; Remote Heat/Cool Volt-Free Contact - Carrier 30GX Installation, Operation And Maintenance Instructions

3.4.4 - Evaporator heater contactor control

The evaporator heater contactor can be supplied with 24 V a.c.
and a maximum current of 0.5 A* between terminals 41 and 12.
Fig. 6 - Evaporator heater connections
3.4.5 - Remote stop/start volt-free contact**
The remote stop/start contact is only taken into account if the
unit is in remote control operating type (rEM). See section
4.2.2.
Remote stop/start connections
Key:
Contact open: unit stopped
Contact closed: start command
NOTE: In exceptional circumstances this contact can be
configured as active (configuration by Carrier Service) if the
unit operates in CCN mode as part of a master-slave link (see
section 5.18).
3.4.6 - Remote volt-free contact for cooling temperature
setpoint selection**
The remote contact for cooling setpoint selection is only taken
into account if the unit is in remote control operating type (rEM).
See section 4.2.2.
Connection for remote setpoint selection
Setpoint selection contact
Key:
Contact open: cooling setpoint 1
Contact closed: cooling setpoint 2

3.4.7 - Remote heat/cool volt-free contact**

The remote heat/cool selection contact is only taken into
account if the unit is in remote control operating type (rEM).
See section 4.2.2.
Connection for remote heat/cool selection
63
Key
Contact open: cool
Contact closed: heat
Start/stop contact
Heat/cool contact
64

3.4.8 - Remote heat reclaim volt-free contact**

This control is used to select the second condensing setpoint or
the heat reclaim mode. It is only taken into account if the unit
is in remote control operating type (rEM). See section 4.2.2.
Connection for heat reclaim mode selection
Heat reclaim selection contact
63
Key:
Contact open: condensing setpoint 1 / reclaim mode not selected
Contact closed: condensing setpoint 2 / reclaim mode selected

3.4.9 - Demand limit volt-free contact**

This contact is used to activate the demand limit function on
the unit (see sections 4.2.10, 4.2.7 and 5.6). This contact is
active whatever the operating type of the unit.
Connection for demand limit contact
Key:
Contact open: demand limit disabled
Contact closed: demand limit active
3.4.10 - Evaporator water loop control and condenser water
flow or thermostat box control volt-free contacts**
If these contacts open, the unit is shut down or prevented from
restarting and an alarm is raised. They are used to control
evaporator and condenser water flow on water-cooled units or
to control the thermostat box temperature on air-cooled units.
Evaporator water-loop control contact connection
Evaporator water loop
control contact
The evaporator water flow control contact is factory-wired (34-
35). The evaporator pump must be controlled and connected
between terminals 34 and 36.
Notes:
* Each output (sections 3.4.1 to 3.4.4) can be supplied
individually at 24 V a.c. - 0.5 A maximum, provided
the total does not exceed 1 A.
** The volt-free contacts (sections 3.4.5 to 3.4.10) are
internally supplied by electric boards under 24 V a.c.
from 15 to 20 mA. The field-supplied volt-free contact
must be compatible with these electrical specifications.
64
Demand limit contact
35
9