13
I-RIH (05-21) 131793-A
Gas Pressure
⚠ CAUTION ⚠
• The main supply line pressure must be limited to 14 IN WC. If the line pressure can go above 14
IN WC (1/2 psi) at any time, a separate positive lockup, high-pressure type, service regulator must
be used. Always check local codes for gas venting requirements for high-pressure regulators.
High-pressure regulators will NOT turn off the flow of gas.
• The minimum supply line pressure at the inlet to the heater regulator must, in no case, be lower
than 7 IN WC pressure for natural gas and 11 IN WC pressure for LP gas.
•
Use a water or red oil manometer when checking gas pressure . Do not use a dial gauge . All measurements must
be made when this heater and all other gas burning equipment are operating at maximum capacity .
•
Natural gas models are orificed for 1,000 BTU per cubic foot of gas (37MJ/m
3
) . Propane models are orificed for
2,500 BTU per cubic foot of gas (93MJ/m
3
) .
•
for gas pressure requirements .
Table 7. Gas Pressure Requirements
Gas Type
Supply Pressure
Manifold Pressure
*
Minimum
Maximum
IN (cm) WC
Natural gas
7 (18)
14 (35)
6 (15)
Propane
11 (28)
14 (35)
10 (25)
*
Measured at the pressure tap in the gas valve .
Electrical Connections
⚠ WARNING ⚠
• The heater must be electrically grounded in accordance with the National Electric Code, ANSI/
NFPA 70 (latest edition), or the Canadian Electrical Code, CSA C22.1 (latest edition).
• The electrical supply wiring to the heaters using 120 VAC or 24 VAC must be installed in accordance
with local codes or the National Electric Code, ANSI/NFPA 70 (latest edition).
• The following types of grounding are NOT permitted by code: grounding to building structures,
grounding to electrical conduit, grounding to gas pipelines, or grounding to water pipelines.
• Electrical supply lines SHALL NOT be used to support the heater.
• DO NOT run electrical wiring above the heater or in direct view of radiant heat.
⚠ CAUTION ⚠
• IMPORTANT! The electrical power supply MUST be properly grounded and properly polarized. The
heater controls are extremely polarity sensitive and the heater will cycle ON and OFF erratically
if the electrical supply is not wired correctly. Have a qualified electrician check to ensure that the
electrical supply circuit is properly grounded and that the electrical supply polarity is correct.
• The electrical power supply must be connected to a circuit breaker or to a separately fused circuit
with a disconnect.
• Important: In the event of an electrical fault after installation of the appliance, preliminary system
checks are required to be carried out, i.e. ground continuity, polarity and resistance to ground,
by a trained and qualified electrician.
•
A heater or group of heaters can be controlled by a thermostat or manual switch . Total load of all heaters must be
considered in determining the required contact rating of the controlling thermostat or switch .