THERMOSTAT
The room thermostat should be located on an inside wall
approximately 56" above the floor where it will not be subject
to drafts, sun exposure or heat from electrical fixtures or
appliances. Follow manufacturer’s instructions enclosed with
thermostat for general installation procedure. Seven color
coded insulated wires (#18 AWG) should be used to connect
thermostat to unit.
POWER AND CONTROL WIRING
Field wiring to the unit must conform to provisions of the
National Electrical Code, ANSI / NFPA No. 70 (in U.S.A.),
current Canadian Electrical Code C22.1 (in Canada) and/or
local ordinances. The unit must be electrically grounded in
accordance with NEC and CEC (as specified above) and/or
local codes. Voltage tolerances which must be maintained at
the compressor terminals during starting and running
conditions are indicated on the unit Rating Plate and Table 1.
The internal wiring harness furnished with this unit is an integral
part of a ETL and CGA design certified unit. Field alteration to
comply with electrical codes should not be required.
A fused disconnect switch should be field provided for the unit.
The switch must be separate from all other circuits. Wire entry
at knockout openings require conduit fittings to comply with
NEC (in U.S.A.), CEC (in Canada) and/or local codes. Refer to
Figure 10 for installation location. If any of the wire supplied
with the unit must be replaced, replacement wire must be of
the type shown on the wiring diagram and the same minimum
gauge as the replaced wire.
Electrical line must be sized properly to carry the load. USE
COPPER CONDUCTORS ONLY. Each unit must be wired with
a separate branch circuit fed directly from the meter panel and
properly fused.
CAUTION: When connecting electrical power and control
wiring to the unit, waterproof type connectors
MUST BE USED so that water or moisture cannot
be drawn into the unit during normal operation. The
above waterproofing conditions will also apply
when installing a field-supplied disconnect switch.
Refer to Figure 5 for typical field wiring and to the appropriate
unit wiring diagram for control circuit and power wiring
information.
OPTIONAL ELECTRIC HEATERS (DCE Models)
The factory installed heaters are wired for single point power
supply. Power supply need only be brought into the single point
terminal block and thermostat wiring to the low voltage terminal
block located in the upper portion of the unit control box.
These ETL and CGA approved heaters are located within the
central compartment of the unit with the heater elements
extending into the supply air chamber. Refer to Figure 10 for
access panel location.
Fuses are supplied, where required, by the factory. Some KW
sizes require fuses and others do not. Refer to Table 1 for
minmum CFM limitations and to Table 6 for electrical data.
COMBUSTION DISCHARGE (DCG Models)
The products of combustion are discharged horizontally
through two screened (hooded) openings on the upper gas
heat access panel.
GAS PIPING (DCG Models)
Proper sizing of gas piping depends on the cubic feet per hour
of gas flow required, specific gravity of the gas and the length
of run. “National Fuel Gas Code” Z223.1 (in U.S.A.) or the
current Gas Installation Codes CAN/CGA-B149.1 and .2 (in
Canada) should be followed in all cases unless superseded by
local codes or gas utility requirements. Refer to Table 3.
The heating value of the gas may differ with locality. The value
should be checked with the local gas utility.
NOTE: There may be a local gas utility requirement specifying
a minimum diameter for gas piping. All units require a
1 inch pipe connection at the entrance fitting.
GAS CONNECTION (DCG Models)
The gas supply line can be routed through the knockouts
located on the front of the unit or through the opening provided
in the unit’s base. Refer to Figure 10 to locate these access
openings. Typical supply piping arrangements are shown in
Figures 6 and 7. All pipe, fittings, etc. are field-supplied.
Two grommets are shipped in the blower compartment (in parts
bag taped to the blower housing) of every unit with gas heat
and should be used in the knockouts when the gas piping
enters through the front of the unit.
After the gas supply piping has been installed, the bottom
opening in the unit should be sealed to prevent water from
leaking into the building.
Gas piping recommendations:
1. A drip leg and a ground joint union must be installed in the
gas piping.
2. When required by local codes, a manual shut-off valve may
have to be installed outside of the unit.
3. Use wrought iron or steel pipe for all gas lines. Pipe
compound should be applied sparingly to male threads
only.
Input Capacity (Mbh)
Output Capacity (Mbh)
Gas
Rate
2
(Ft.
3
/Hr.)
Temp.
Rise
°
F
At
Full Input
3
0 To
2,000 Feet
Above
Sea Level
2,000 To
4,500 Feet
Above
Sea Level
1
0 To
2,000 Feet
Above
Sea Level
2,000 To
4,500 Feet
Above
Sea Level
1
Max.
Min.
Max.
Min.
Max.
Max.
Min.
Max.
300
150
270
135
240
213
279
20
50
400
200
360
180
320
281
372
30
60
NOTE: Heaters are shipped available for natural gas, but can be converted to
L.P. / Propane with Kit Model No. 1NP0418.
1
MBH rating should be reduced at the rate of 4 percent for each 1,000 feet above 4,500 feet.
2
Based on maximum input and 1075 Btu/Ft
3
.
3
The air flow must be adjusted to obtain a temperature rise within the range shown.
TABLE 2 - GAS HEAT APPLICATION DATA
FIG. 6 - EXTERNAL SUPPLY CONNECTION
EXTERNAL SHUT-OFF
Length in Feet
Nominal Iron Pipe Size
1 in.
1-1/4 in.
10
20
30
40
50
60
70
80
90
100
520
350
285
245
215
195
180
170
160
150
1,050
730
590
500
440
400
370
350
320
305
Maximum capacity of pipe in cubic feet of gas per hour. (Based upon a pressure drop of 0.3
inch water column and 0.6 specific gravity gas).
TABLE 3 - PIPE SIZING
530.18-N11Y
6
Unitary Products Group
