For Natural Gas: Check the furnace rate by observing the gas meter, when available, making sure all other gas appliances are turned off. The test hand on the meter should be timed for at least one revolution. Note the number of seconds for one revolution.
BTU/HR | = | Cubic Feet Per Revolution x 3600 x Heating | |
INPUT |
| # Seconds Per Revolution | Value |
The heating value of the gas can be obtained from the local utility company.
For Propane Gas: The only check for the furnace rate is to properly adjust the manifold pressure using a manometer and the information provided in Table 12. Typical manifold set point for installations at altitudes from 0 to 4500 feet above sea level is 10.0" W.C.
Temperature Rise
Check the temperature rise and, if necessary, adjust blower speed to maintain temperature rise within the range shown on the unit rating plate.
High Altitude
In both the United States and Canada, this furnace is approved for operation at altitudes from 0 to 4500 feet above sea level without any required modifications. From 4500 to 7500 feet, the gas manifold pressure needs to be adjusted
according to the information shown in Table 12. To adjust the manifold pressure, refer to previous section Checking and Adjusting Gas Input. For installations above 7500 feet, call Technical Service at
For installations above 4500 feet fill in the appropiate information on the furnace label that has the words “This furnace was converted on . . . . . . “.
Emergency Replacement Motor Operation
If the variable speed motor needs to be replaced in an emergency situation (such as “no heat”) and an exact replacement motor is not immediately available, a standard PSC motor of equivalent frame size, voltage, rotation, and horsepower can be temporarily installed until the correct replacement motor can be obtained.
Connect the desired speed tap to the “EAC” terminal and the neutral tap to the neutral terminal on the ignition control (refer to the furnace wiring diagram). T he ignition control will control the motor’s operation, including a nominal 20 second “on” delay with a call for heat and a nominal 180 second “off” delay when the thermostat is satisfied. It will also operate the motor on a call for cooling, with no “on” or “off” delays.
Verify that the unit is operating at the desired speed and within the rise range as shown on the unit rating plate.
The correct replacement motor must be installed as soon as possible to ensure continued satisfactory operation of the furnace.
MANIFOLD PRESSURE SETTINGS
*Consult local utility for actual heating value. Furnace input = Input Factor x Nameplate Input
NOTE: A natural to LP/Propane gas changeover kit is necessary to convert this unit. Refer to the changeover kit installation instruction for the conversion procedure.
Table 12
Page 34 of 41 | Issue 1034 |
