GPG16M Service Manual
SERVICING
54
HIGH VOLTAGE!
Disconnect ALL power before servicing
or installing this unit. Multiple power
sources may be present. Failure to do so
may cause property damage, personal injury
or death.
1. Remove wires from the electrical terminals.
2. Using a VOM check from Common to NO (Normally
Open) - should read open.
If switch reads as noted proceed to Step 3, otherwise
replace control.
3. Remove the pressure control hose from the control and
interconnect with an inclined manometer as shown:
PRESSURE SWITCH
INCLINED
MANOMETER
1/4" COPPER TEE
HOSE
TO J-TUBE
Reconnect wires to the Common and NO terminals.
With Power ON:
WARNING
Line Voltage now present.
4. Energize furnace for heating cycle. The induced draft
blower motor will begin to run. The inclined manometer
should read approximately -1.2" ± 0.3" W.C with no
combustion.
5. Remove and check the two electrical wires and using the
VOM check from Common to NO (Normally Open), it
should read closed (with I.D. motor running). If not as
above, replace pressure control.
6. Reconnect all wires to the control and place in heating
cycle.
7. As the unit fires on high stage, the inclined manometer
negative pressure will drop to -1.0" ± 0.3" W.C.
8. If not as listed, replace control.
Note: the pressure switch must be mounted with the dia-
phragm in a vertical position.
S-311 HIGH ALTITUDE APPLICATION
High Altitude Derate - U.S. Installations
Only
IMPORTANT NOTE: The gas/electric units naturally derate
with altitude. Do not attempt to increase the firing rate by
changing orifices or increasing the manifold pressure. This
can cause poor combustion and equipment failure. At all
altitudes, the manifold pressure must be within 0.3 inches
W.C. of that listed on the nameplate for the fuel used. At
all altitudes and with either fuel, the air temperature rise
must be within the range listed on the unit nameplate.
Refer to the Installation Manual provided with the LP kit for
conversion from natural gas to propane gas and for altitude
adjustments.
When this package unit is installed at high altitude, the
appropriate High Altitude orifice kit must be installed. As
altitude increases, there is a natural reduction in the
density of both the gas fuel and combustion air. This kit will
provide the proper design certified input rate within the
specified altitude range. High altitude kits are not approved
for use in Canada. For installations above 2,000 feet, use
kit HA-03. The HA-03 kit is used for both Natural and LP gas
at high altitudes.
Use LPM-08 (2 stage heat models) or LPM-07 (1 stage heat
models) propane conversion kit for propane conversions at
altitudes below 2000 feet. Natural gas installations below
2000 feet do not require a kit.
For propane conversions above 2000 feet, high altitude kit
HA-03 is required in addtion to the propane conversion kit.
Natural gas and LP gas installations at altitudes > 2000 ft
2000 3000 4000 4500 5000 6000 7000 8000
U.S. BURNER ORIFICE 44/55 44/55 45/56 -- 45/56 46/57 47/58 47/58
CANADA BURNER ORIFICE 44/55 -- -- 47/57 -- -- -- --
2000 3000 4000 4500 5000 6000 7000 8000
U.S. BURNER ORIFICE 43/55 43/55 44/56 -- 44/56 44/56 45/57 45/57
CANADA BURNER ORIFICE 43/55 -- -- 46/57 -- -- -- --
2000 3000 4000 4500 5000 6000 7000 8000
U.S. BURNER ORIFICE 45/55 47/55 47/56 -- 47/56 48/57 48/58 49/58
CANADA BURNER ORIFICE 45/55 -- -- 48/57 -- -- -- --
INPUT/BURNER
20,000 BTUH NAT/20,000 BTUH/L.P.
ELEVATION ABOVE SEA-LEVEL (FEET)
INPUT/BURNER
22,500 BTUH NAT/20,000 BTUH/L.P.
ELEVATION ABOVE SEA-LEVEL (FEET)
INPUT/BURNER
25,000 BTUH NAT/20,000 BTUH/L.P.
ELEVATION ABOVE SEA-LEVEL (FEET)