MUA-SVX01A-EN • Direct-Fired Make-up Air
65
Trouble Shooting
3.
Turn test potentiometer slowly to maximum resistance. The DC voltage
should gradually increase to at least 18 volts. If proper voltages are observed
in both Section 1 and 2, the amplifier is satisfactory. If proper voltages are not
observed, continue testing to identify the difficulty. Faults may be identified
with the amplifier, the 24V power supply, or the circuit connected to terminals
#6 and #7.
Section 3
Observe burner flames and/or burner pressure as test potentiometer is turned
through full range.
Note: From 0-5 volts, heater should be at bypass or low; 5-15 volts heater should
respond with various input rates; beyond 15 volts, heater is at maximum
input.
If proper operation is observed, continue procedure to check operation of sensing
and selecting components.
If operation is not observed, see trouble shooting section to test M or MR valves
and connecting wiring.
Figure 23. Wire 2 Diagram
2
4
5
6
7
8
9
1
3
14V20A
Transf.
Valve
10K Test
POT
2K
Resistor
Jumper
MDT/MRT Controls
