Low Voltage Interface Connections - Friedrich VERT-I-PAK R410A Service & Parts Manual

Low Voltage Interface Connections

All Vert-I-Pak units have a low voltage interface connector through
which a Remote Wall Thermostat, Desk Control and Auxiliary Fan's
Relay can be connected. The interface connector is located on the
electronic control board.
Figure 1 Interface Connector Location
Questions concerning proper connections to the unit should be dirrected
to the factory.
Table 1
Interface Connector Definitions
Factory use only.
FP
(Ensure there is no jumper at FP an F2)
Used with F1 to provide 24 VAC to external
F2
fan relay. (Ensure there is no jumper at FP an F2)
Used with F2 to provide 24 VAC to
F1
external fan relay.
Used with D1 for desk control on or off
D2
operation.
Used with D2 for desk control on or off
D1
operation.
Common Ground Terminal
C
Call for high fan
GH
Call for low fan
GL
B Call for heat pump reversing valve
Call for compressor
Y
W
Call for heating
R 24V Power from Electronic Control to Wall
Remote Wall Thermostat
All Friedrich Vert-I-Pak units are factory configured to be controlled by
using a single stage heat/cool remote wired wall mounted thermostat.
12
Thermostat Selection
Friedrich recommends the use of the Friedrich RT4 and RT6. These
thermostats are single stage heat/cool, manual changeover. The RT4 is a
digital display thermostat with single speed fan control. The RT6 features
a digital display, two fan speed selection, temperature limiting, status
indicator light, room temperature offset, and backlight. Other thermostats
may be used as long as they are single stage heat/cool and are
configured correctly for the unit.
Thermostat terminals requirements:
.
For cooling with electric heat units: C, R, G, Y, W.
For heat pump units: C, R, G, Y, W, B.
For two fan speeds, thermostat must have 2 fan speed selection.
HEAT PUMP UNITS
During Heat Mode:
The B terminal must be continuously energized. The W terminal must have
24 VAC output to call for heat. The control board decides on whether to
turn on the Heat Pump Heat (compressor) or Electric Heat. The Y terminal
should not have 24 VAC output during heat mode.
Connecting a Remote Wall
Thermostat
WARNING
ELECTRIC SHOCK HAZARD
Disconnect power to the unit before
servicing. Failure to follow this warning
could result in serious injury or death.
Connect the thermostat using Figure 1 and Table 1 as a guide.
Procedure (Ensure there is no jumper wire at FP and F2)
1) Disconnect power to the unit.
2) Unscrew and remove the electrical control box's cover.
3) Locate the Interface Connector (24 VAC terminal strip (See figure 1 at left).
4) Make the wire connections according to the con figuration needed for
your unit (see above or page 40 for wiring diagrams). Use #18 gauge wire size.
5) Once each wire is matched and connected, the unit is now ready to be
controlled by the thermostat.
6) Reattach the electrical control box's cover.