Fan and limit control – Carrier 58BB User Manual
Page 9
Attention! The text in this document has been recognized automatically. To view the original document, you can use the "Original mode".
1
•>
58BD NATURAL GAS BURNERS
WITH UNITROL 7000 GAS VALVE
58BB NATURAL GAS BURNERS
WITH ESSEX TF 555 GAS VALVE
\
58BB PROPANE GAS BURNERS
WITH ESSEX TF 555 GAS VALVE
58BD PROPANE GAS BURNERS
WITH UNITROL 7000 GAS VALVE
Fig. 8 — 58BB,BD Gas Burners and Manifold Assemblies
2. For belt drive speed change (58BD furnaces),
perform the following;
a. Loosen setscrew on adjustable hub of motor
sheave.
b.
Rotate hub clockwise to increase or
counterclockwise to decrease speed and
tighten setscrew on flat hub section.
Belt Adjustment
Adjustment is correct if one-finger pressure
depresses center of belt 1 inch. Each blower speed
change on a 58BD furnace requires a belt
adjustment.
1. Loosen locknut.
2. Turn adjusting screw on motor mounting
bracket in to tighten or out to loosen.
3. Tighten locknut.
Fan and Limit Control
1. Constant air circulation provides even temper:
ture control. The lower the fan switch settin;
the longer the fan will continue to run afti
burners turn off.
2. After running furnace for 15 minutes, restri^
the return air supply by blocking the filters (
by closing the return registers.
3. Allow furnace to shut down on high hmit. F:
must continue to run.
4. Remove restriction. Burners should come on
a few minutes.
5. Adjust “Off” setting per installation needs.
“On” setting is 25 F above “Off” settii
differential is not adjustable.