PH
-SERIES
41
17.0
GAS INPUT RATE
WARNING:
Natural gas heating values can vary widely. It is the responsibility of the Installer to make sure that the input
rate to the heater as installed does not exceed the nameplate rating of the heater. Failure to do so can cause
radiant tube failure, resulting in injury or death.
The maximum BTUH input capacity for each model is shown on the heater's rating plate and in the specification
table. This input must not be exceeded.
The input shown may be used in geographic area where the elevation is from 0 to 4,500 feet (1372m) above
sea level (Canada only) in accordance with CGA 2.17-M91 (R2003), no change required to main orifice. For
installations above 4,500 (1372 m) refer to
Natural Gas and Propane Installation Code, CSA
B149.1
or latest
edition, or contact the factory. In the USA: For installations above 2000 feet (610 m), the appliance shall be de-
rated 4 percent (%) for each 1000 feet (305 m) of elevation above sea level. The Btu/hr input depends on the
calorific heating value of the gas, orifice size, and manifold pressure. Orifice sizes are based upon values of
1000 Btu/hr/cu. ft (.028316 cubic meter) and 2500 Btu/hr/cu. ft. (.028316 cubic meter) for L.P.G. (propane).
WARNING:
NEVER ATTEMPT TO MODIFY THIS HEATER - FIRE, EXPLOSION, OR ASPHYXIATION MAY RESULT.
If
malfunction is apparent, contact qualified service agency and or gas utility for assistance.
How to Determine Gas Input Rate:
Where gas is metered, the input rate may be determined by the following method, Contact the gas supplier,
Public Utility Company or Propane gas distributor to obtain the calorific gas value of the gas being used. When
checking the gas input rate, any other gas burning appliances connected to the same meter must be completely
off. The heater should be allowed to operate for 5 minutes before attempting to check the gas input rate.
To check flow rate, observe the one cubic foot dial on the gas meter and determine the number of seconds
required for the dial hand to complete one revolution (seconds to flow one cubic foot).
To determine the number of seconds per cubic foot that is necessary to achieve the correct input rate, use the
following formula:
GAS VALUE X
3600 /
DESIRED INPUT = SECONDS NEEDED
Example: 1000 BTU gas, heater input 100,000 BTUH
Seconds for one cubic foot = 1000 X 3600 /100,000 = 36 seconds
If when clocking the meter, the one cubic foot dial makes a complete revolution in less time than was calculated
that it should be de-rated. It if takes more time for the meter to make one revolution than was calculated, the
unit is under-fired.
The orifice size must be changed to correct an over-fired or under-fired condition. If it is determined that
different orifices are needed, please contact your distributor for assistance in selecting the correct
replacement.
