17
SETTING THE THERMOSTAT HEAT ANTICIPATOR
The method shown below should be used in measuring the amp draw of the low voltage circuit to assure proper adjustment
of the thermostat heat anticipator.
WRAP THE THERMOSTAT WIRE 10 TIMES AROUND
THE METER LEG AND DIVIDE THE RESULT BY 10
EXAMPLE:
IF METER READS 4 AMPS
SET THE HEAT ANTICIPATOR
AT .4 (4/10 = .4).
"W" FROM ROOM
THERMOSTAT
CLAMP ON AMP METER
TO RATE FURNACE
GENERAL
The meter time and orifice sizes indicated in these instructions are for equipment to be installed using Natural Gas. If Propane
Gas is used refer to instructions supplied with the conversion kit. High Altitude application requires the conversion kit HAO2.
It is important to check the furnace input to prevent over firing beyond the design-rated input. NEVER SET INPUT ABOVE
THAT SHOWN ON THE RATING PLATE. Furnace firing rate is controlled by inlet pressure, manifold pressure, burner orifices,
heating value of the gas. This furnace is equipped with the correct burner orifices for installations between 0 to 2000 feet and
normally do not have to be changed. Applications over 2000 feet require factory equipped orifices to be replaced by burner
orifices selected from the table below resulting in the furnace input being reduced at a rate of 4% for each 1000 feet above
sea-level (U.S. only).
ALTITUDE BURNER ORIFICE
NATURAL GAS
0-2000 45
3000
47
4000
47
5000
47
6000
48
7000
48
For altitudes above 7000 feet refer to appropriate section of the National Fuel Gas Code, ANSI Z223.1. If re-orificing is required
this must be performed prior to timing the gas meter. THE GAS AND ELECTRIC SUPPLY MUST BE OFF BEFORE
INSTALLING NEW BURNER ORIFICES. To calculate the furnace input of a furnace installed over 2000 feet you must use
the following formula and not the table supplied.
CORRECTED INPUT (BTUH) = NAMEPLATE INPUT - (ALTITUDE x .04) x (NAMEPLATE INPUT / 1000)
Input BTU/HR = Heating Value of Gas (BTU/FT3) x 3600
Time in Second (for 1 cu.ft.) of Gas
HIGH ALTITUDE CONVERSIONS FOR CANADIAN INSTALLATIONS :
In Canada the name plate input rating for the furnaces apply if\or installations up to 2,000 feet (610 m) above sea level. Kit
No. HA02 for Natural Gas and for Propane Gas is required to convert the furnaces to elevations from 2,000 to 4,500 feet (610
to 1,370 m) above sea level. Canadian Certification applies to the Installations of furnaces up to 4,500 feet (1,370 m) above
sea level. Installations above 4,500 feet (1,370 m) above sea level is subject to acceptance by the local authorities having
jurisdiction.
Summary of Contents for GMN SERIES
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