FloAire FAV-M - Manual (Page 37)

37
Maxitrol Preliminary Circuit Analysis Series 44 System
The basic Series 44 system consists of an amplifier, a discharge-air monitor with mixing tube, a
selectrastat, and a modulating valve or a modulator-regulator valve.
Series 44 Wiring for Preliminary Testing Procedures:
•
Turn the test potentiometer to 2,000-Ohm minimum resistance. The dc voltage should read 0-V.
Slowly turn the test potentiometer to maximum resistance or 12,000-Ohms. The dc voltage
should gradually increase to at least 18-V.
•
If proper voltages are observed, continue with the following test procedures.
•
If proper voltages are not observed, the problem is identified with the amplifier, the 24-V ac power
supply, or the circuit connected to Terminals 6 and 7.
•
Turn power OFF. Wire system as shown. Turn power back ON.
•
Turn the test potentiometer to minimum resistance. The dc voltage should read 0-V. Slowly turn
the test potentiometer to maximum resistance. The dc voltage should gradually increase to at
least 18-V.
•
If proper voltages are observed, continue with the following test procedures.
•
If proper voltages are not observed, the problem is identified with the amplifier, the 24-V ac power
supply, or the circuit connected to Terminals 6 and 7.
•
Observe burner flame and burner pressure as test potentiometer is turned through full range.
o 0 to 5-V The heater should be at bypass or low.
o 5 to 15-V The heater should respond to various input rates.
o 15-V and up The heater is at maximum input.
•
If proper voltages are observed, continue procedures to check
operation of sensing and selecting components.
•
If proper voltages are not observed, see checklist on the following
page to test the MR212 or M611 modulating valve and
connecting wiring.
•
With proper voltages present and modulator responding correctly,
return to the wiring configuration as shown below, except have
the
TS144 discharge-air monitor connected in place of the jumper. Set
minimum-temperature selector at least 10° F above outdoor
temperature. Set maximum-temperature selector at mid-range.
Heater is now under control of the discharge-air monitor.
•
Turn test potentiometer to maximum resistance. Air temperature
should be at maximum-temperature setting. Turn test
potentiometer to minimum resistance. Delivered air temperature
should be at minimum temperature setting.
•
If proper voltages are not observed, check calibration. See
checklist on the following page.
•
If proper voltages are observed, the problem is identified with the space temperature sensing and
temperature selecting components and circuits.
•
After these preliminary test procedures are completed, remove all test equipment and reconnect
components.