Airmark GFW SERIES Installation & operating instructions manual - page 7
IO-123090-GFW-020113
- 7 -
©2013 AirMark
Fig. 6. shows the components of a typical TXV
assembly
TXV BULB
TAIL PIECE
DISTRIBUTOR
TEFLON O-RINGS
Fig.6. Components of a typical TXV assembly
CAUTION
Using a non-bleed expansion valve
may require the use of a hard-start kit. Follow the
outdoor unit manufacturer’s guidelines.
Electrical Installation
These units are designed for single phase 120
volts, 60 Hz power supply. Wire selection and
wiring must be in accordance with the National
Electric Code and/or local codes. Unit terminals
are designed to accommodate copper and
aluminum wirings. If aluminum wiring is used;
please observe special precautions relative to
sizing, wire connections and corrosion protection.
Fig.7 shows the typical electrical connections
required for A/C only and heat pump applications.
The unit ships with a micro-processor based board
which controls the electrical functioning of the unit.
An inspection of the controls is recommended prior
to start-up.
Fig.8 provides a schematic of the control board
present in the unit. The units ship from the factory
with the aquastat jumper in the OFF position (right
two pins) and the heating selector in the HW
position (right two pins). If an aquastat is used in
the application; the jumper should be changed to
ON position (left two pins).
Note: Terminals T and N located on the top right
side of the board are not intended for field use and
should be left un-connected.
CAUTION
The aquastat (AQ) jumper must be
in the OFF position at all times; except for when an
aquastat is used. If the jumper is moved to the ON
position without installing an aquastat the blower
will not be energized.
When an aquastat is present, the blower will be
energized at the aquastat temperature settings.
Fig 7. Electric connections
On units shipped from factory with a pump installed
the pump will be energized on call for heat.
In units that were shipped without factory installed
pumps, two black wires should be connected to the
boiler terminals T T. In applications where a boiler
provides the hot water supply, these wires shouId
be connected to the boiler. Terminals T T are
normally open dry contacts.
In applications where a valve is used to regulate
hot water supply, the two black wires located on
the T T terminals should be removed and placed
on the two terminals reading “VALVE”. The open
ends of the wires should be connected to the valve
according to local requirements and instructions of
the valve manufacturer. On call for heat, 24V will
be sent to the field-installed valve or pump relay.
On call for heat water will circulate through the
water (hydronic) coil for 60 secs prior to energizing
the blower. After the thermostat is satisfied, the
blower will continue to stay energized for a
minimum of 30 secs. This helps maximize heating
efficiency.