I Electric Furnace
Changing Motor Speed
The blower motor comes from the factory wired for medium or high speed. To change the blower speed, disconnect the black wire at the blower motor termina! block and reconnect at the de- sired blower speed tap.
Figure 10 I Typical Low Voltage Connections
Installation Instructions
Air Flow Check
For proper system operation, the air flow through the indoor coil should be between 350 and 450 cfm per ton of cooling capacity. The air flow through the unit can be determined by measuring the external static pressure to the unit and selecting the motor speed tap that will most closely provide the required air flow.
1. Set up to measure external static pressure at the supply |
and return duct connections (Figure 11). |
Thermostat Cooling Only
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Outdoor Unit
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2. | Drill holes in the ducts for pressure | taps, pitot tubes, or oth- | |
| er accurate pressure sensing devices. |
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3. | Connect these taps to a level inclined | manometer or draft | |
| gauge. |
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4. | Ensure the coil and filter are clean, | and | all the registers are |
| open. |
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5. | Determine the external static pressure | with the blower op- | |
| erating. |
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6. | Refer to the Air Flow Data (Figure | 6) table to find the speed | |
| tap that will most closely provide the required air flow for the | ||
| system. |
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7. | Refer to Changing the Motor Speed in these instructions if | ||
| the speed tap is to be changed. |
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W 2 W 1 G Y O H C R 1
Indoor Blower
8. Recheck the external static pressure with the new speed |
tap, and confirm speed tap selection. |
Thermostat
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Cooling with Electric Heat
Figure 11 | Static Pressure Check |
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Outdoor Unit
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Heat Pump with Electric Heat
Staging
Thermostat
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Outdoor Unit
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Return _
Maintenance
Filters
Filters must be cleaned when they become dirty. Inspect at least once per month. The frequency of cleaning depends upon the hours of operation and the local atmospheric conditions. Clean fil- ters keep unit efficiency high.
Lubrication
The bearings of the blower motor are permanently lubricated.
Condensate Drains
During the cooling season check the condensate drain lines to be sure that condensate is flowing from the primary drain but not from the secondary drain. If condensate ever flows from the sec-
ondary drain the unit should be promptly shut off and the conden- sate pan and drains cleaned to insure a free flowing primary drain.
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