Electrical Power; Nominal Manifold Pressure - High Fire - Johnson Controls MG9S*MP Installation Manual

6. Remove LP (propane) orifices from the bag in the Customer
Packet.
7. Install the LP (propane) gas orifices supplied with the furnace.
Tighten to 15 - 25 inch - pounds of torque.
8. Reinstall the manifold in the assembly by reversing the removal
process.
9. Reconnect the wires to the proper terminals on the gas valve.
10. Unscrew the gas valve regulator with the blue cap and turn it
upside down so the letters "LP" are upright. Replace the blue cap
on the regulator.
11. Remove the natural gas tag and replace with the propane gas tag
supplied in the orifice bag.
12. Remove the blue conversion label on the furnace door after the
furnace has been converted.
13. Reconnect the gas supply piping to the gas valve and insure that
all gas connections are tight.
14. Remove pressure tap plugs from gas valve and connect water
gauge to the pressure tap ports. See Figure 14 for location of the
gas valve pressure taps and pressure regulator adjustment.
15. Turn on gas supply to furnace and check all gas connections with
suitable leak detector.
Table 5: Nominal Manifold Pressure - High Fire
Manifold Pressures (in wc)
800
850
900
950
1000
1050
1100
2500 (LP)
PROPANE AND HIGH ALTITUDE CONVERSION KITS
It is very important to choose the correct kit and/or gas orifices for the altitude and the type of gas for which the furnace is being installed.
Only use natural gas in furnaces designed for natural gas. Only use propane (LP) gas for furnaces that have been properly converted to use pro-
pane (LP) gas. Do not use this furnace with butane gas.
Incorrect gas orifices or a furnace that has been improperly converted will create an extremely dangerous condition resulting in premature heat
exchanger failure, excessive sooting, high levels of carbon monoxide, personal injury, property damage, a fire hazard and/or death.
High altitude and propane (LP) conversions are required in order for the appliance to satisfactory meet the application.
An authorized distributor or dealer must make all gas conversions.
In Canada, a certified conversion station or other qualified agency, using factory specified and/or approved parts, must perform the conversion.
The installer must take every precaution to insure that the furnace has been converted to the proper gas orifice size when the furnace is installed.
Do not attempt to drill out any orifices to obtain the proper orifice size. Drilling out a gas orifice will cause misalignment of the burner flames,
causing premature heat exchanger burnout, high levels of carbon monoxide, excessive sooting, a fire hazard, personal injury, property damage
and/or death.
SECTION V: ELECTRICAL POWER
ELECTRICAL POWER CONNECTIONS
Field wiring to the unit must be grounded. Electric wires that are field
installed shall conform to the temperature limitation for 63°F (35°C) rise
wire when installed in accordance with instructions. Refer to Table 6 in
these instructions for specific furnace electrical data.
Johnson Controls Unitary Products
Altitude (feet)
0-7999 8000-8999 9000-9999
3.5 3.5
3.5 3.5
3.5 3.5
3.5 3.5
3.5 3.2
3.5 2.9
3.2 2.7
9.8 8.2
Never use an open flame to check for leaks. Fire or explosion
could occur. Since some leak solutions including soap and
water may cause corrosion or stress cracking, the piping must
be rinsed with water after testing unless it has been determined
that the leak test solution is non-corrosive.
HIGH ALTITUDE GAS ORIFICE CONVERSION
This furnace is constructed at the factory for natural gas-fired operation
at 0 –7,999 feet (0-m – 2,438 m) above sea level.
The manifold pressure must be changed in order to maintain proper
and safe operation when the furnace is installed in a location where the
altitude is greater than 7,999 feet (2,438 m) above sea level. Refer to
Table 5 for proper manifold pressure settings.
HIGH ALTITUDE PRESSURE SWITCH CONVERSION
For installation where the altitude is less than 5,000 feet (1,524m), it is
not required that the pressure switch be changed unless you are in an
area subject to low pressure inversions.
For altitudes above 5,000 feet, see kits below.
S1-1PS3306 - 080
S1-1PS3307 - 060
S1-1PS3302 - 100, 120
3.5 29.8
3.5 31.7
3.5 33.5
3.3 35.4
2.9 37.3
2.7 39.1
2.4 41.0
7.5 93.2 (LP)
Use copper conductors only.
420705-UIM-C-0310
Manifold Pressures (kpa)
Altitude (m)
0-2437 2438-2742
0.87 0.87
0.87 0.87
0.87 0.87
0.87 0.87
0.87 0.80
0.87 0.73
0.80 0.66
2.44 2.03
2743-3048
0.87
0.87
0.87
0.81
0.73
0.67
0.61
1.86
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