26
Electrical Power Connections
Installations must follow these codes:
• National Electrical Code and any other national,
state, provincial or local codes or regulations hav-
ing jurisdiction.
• Safety wiring must be NEC Class 1.
• Heater must be electrically grounded as required
by the NEC.
• In Canada, CSA C22. 1 C.E.C. Part 1.
The heater is wired for 120 VAC, less than 12 amps in
its basic configuration. Additional options may
increase the amp draw of the unit. The voltage is indi-
cated on the tie-in leads. Consult the wiring diagram
Fig. 28: Gas Valves
Table J: Maximum Equivalent Pipe Length
Natural gas – 1,000 BTU per ft
3
, .60 specific gravity at 0.5 in. WC pressure drop
Propane gas (HD-5) – 2,500 BTU per ft
3
, 1.53 specific gravity at 0.6 in. WC pressure drop
Gas Supply Pressure
A minimum of 5.6 in. WC upstream gas pressure
under full load and a maximum gas supply pressure
set point of 10.5 in. WC under load and no-load condi-
tions are required for natural gas. A minimum of 11.0
in. WC upstream gas pressure under full load and a
maximum gas supply pressure set point of 13.0 in. WC
are required for propane gas. The gas pressure regu-
lator(s) supplied on the heater is for low-pressure
service. If upstream pressure exceeds 14.0 in. WC
(1/2 psi) at any time, an intermediate gas pressure
regulator, of the lockup type, must be installed.
When connecting additional gas utilization equipment
to the gas piping system, the existing piping must be
checked to determine if it has adequate capacity for
the combined load.
The gas valve pressure regulator(s) on the heater are
nominally preset at 3.5 in. WC for natural gas, and
10.5 in. WC for propane gas. The pressure at the gas
valve outlet tap, measured with a manometer, while in
operation should be 3.5 ± 0.1 in. WC for natural gas
and 10.5 in. ± 0.1 in. WC for propane gas. If an adjust-
ment is needed, remove the adjustment screw cover
and turn the adjustment screw clockwise to increase
pressure or counter-clockwise to lower pressure.
M
odel
No.
2” 2-1/2” 3” 4”
N P N P N P N P
992C 120 300 300
1
262C
7
5
1
80
1
70
3
25
5
60
1532C 50 120 125 250 400
1802C 40 100 100 225 340
2002C 30 80 75 175 260
2072C 30 80 75 175 260
2342C 20 55 55 135 160 400 600
NOTE: The maximum allowable pressure drop from
static to dynamic at full fire is 30%.