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Field service checklist, Symptom possible cause field test remedy – Greenheck Maxitrol Series 44 User Manual

Page 4

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4

18

.

If readings are incorrect, replace the TS144 or repair wiring.

1.

Install properly.

16

.

Clean, replace valve and/or seat if necessary.

17

.

Clean, or if necessary, replace plunger.

*Control circuits external to the Series 44 can cause burner malfunction. Always check manual valve to be certain gas is on, a

nd check limit controls for normal operation.

SYMPTOM

POSSIBLE CAUSE

FIELD TEST

REMEDY

5.

Provide 24V AC to amplifier. Refer to item 24.

6.

If proper resistance values are not observed, replace modulator

head or repair wiring.

7.

If readings are incorrect, replace the TS144 or repair wiring.

8.

If power source and modulator coil check ot (items 5 & 6) but

proper modulating voltages cannot be obtained, then amplifier may

be assumed at fault. Install replacement amplifier.

21

.

If amplifier is proven at fault, install replacement ampifier.

22

.

If reading is incorrect, replace the T244, TS244/TD244 or

repair wiring.

23

.

If proper aciton is obtained, first check item 22. Recalibrate if

necessary - page 8.

Field Service Checklist

A.

B.

C.

D.

E.

F.

G.

H.

I.

No gas flow.

1.

Valve improperly installed.

Continuous low fire

(electronics OK).

5.

No voltage to the amplifier.

6.

Short in modulator coil circuit.

7.

Short in TS144 circuit.

8.

Faulty amplifier

Incorrect Low Fire.

9

.

Incorrect by-pass metering valve adjustment.

10

.

Excessive negative burner pressure.

Continuous

Minimum Discharge Air

Temperature.

11

.

Faulty amplifier.

12

.

Short in T244 or TS244/TD244 circuit.

13

.

Incorrect space temperature calibration.

Incorrect Max. or Min.

Discharge Air Temperature.

14

.

Improper TS144 location.

15

.

Incorrect discharge air temperature calibrations.

Continuous High Fire.

(electronics OK)

16

.

Foreign material holding valve open.

17

.

Plunger jammed.

Continuous High Fire.

(electronics problem)

19

.

Inlet pressure too low.

20

.

Incorrect outlet pressure adjustment.

Incorrect High Fire.

21

.

Faulty amplifier.

22

.

Open circuit in T244 or TS244/TD244.

23

.

Incorrect space temperature calibration.

2.

If proper resistance values are not observed, replace modulator

head or repair wiring.

3.

Clean or replace plunger if necessary and install (as in figures

on page 3).

4.

Replace diaphragm if ruptured.

9

.

Adjust to proper low fire.

10

.

If greater than 1.5" negative pressure, check equipment for clogged

filters & other inlet air restrictions. For other solutions, consult Maxitrol.

11

.

If amplifier is proven at fault, install replacement amplifier.

12

.

If reading is incorrect, replace the T244, TS244/TD244 or

repair wiring.

13

.

If proper action is obtained, first check item 12. Recalibrate if

necessary - Pg. 8.

14

.

Move TS144 to location where average temperature can be sensed.

15

.

If proper temperatures are not observed, refer to Discharge Air

Temperature calibration procedures - Page 8.

1.

Arrow on side of valve should point in direction of gas flow.

2.

Remove wires connected to amplifier terminals 6 & 7 and measure resistance.

MR212 (60-80 ohms), M611 (45-55 ohms).

3.

Inspect - plunger should be installed (as in figures on page 3) and operate freely in

solenoid sleeve.

4.

Disassemble valve for inspection of internal parts.

5.

Check for 24V AC at amplifier terminals 8 & 9.

6.

Measure resistance per item 2.

7.

Remove wires connected to amplifier terminals 1, 2, & 3. Measure resistance across

wires 1 & 3, then 2 & 3. Meter should read greater than 2500 ohms.

8.

Follow precedures outlined in "PRELIMINARY CIRCUIT ANALYSIS" (Sections I & II).

9

.

See Valve Adjustments - Page 6.

10

.

Close main gas supply and measure manifold pressure with blower

operating. Should be less than 1.5" w.c. negative pressure

11

.

Follow precedures outlined in "PRELIMINARY CIRCUIT ANALYSIS" (Sections I & II).

12

.

Remove wires connected to amplifier terminals 4 & 5. Set T244 or TD244 to maximum

setting. Measure resistance across wires. Meter should read 6000 ohms

+

1000 (T244).

If TS244/TD244 are used, mete should read 4500 ohms

+ 1000 (TS244) and 2100

ohms

+ 150 (TD244).

13

.

Follow procedures outlined in "PRELIMINARY CIRCUIT ANALYSIS" (Sections IV).

14

.

Compare sensed temperature reading at TS144 with average discharge air temperature.

15

.

Follow precedures outlined in "PRELIMINARY CIRCUIT ANALYSIS" (Sections IV).

19

.

Read inlet pressure at valve, using a manomete with heater operating at full fire.

Pressure should be at least equal to the sum of: outlet pressure setting and pressure

drop of the valve (See Maxitrol Capacity Chart Bulletin) plus 1.0" w.c.

20

.

Read outlet pressure using manomete and compare with recommendation of

equipment manufacturer.

21

.

Follow precedure outlined in "PRELIMINARY CIRCUIT ANALYSIS" (Sections I & II).

22

.

Measure resistance per item 12.

23

.

Follow precedures outlined in "PRELIMINARY CIRCUIT ANALYSIS" (Section IV).

2.

Open circuit in modulator coil.

3.

Plunger missing, jammed or improperly installed.

4.

Ruptured main or balancing diaphragm.

Continuous Low Fire

(electronics problem).

J.

Continuous Maximum

Discharge Air Temperature.

24

.

Short in modulator coil circuit.

24

.

Measure resistance per item 2.

25

.

If desired temperature is not reached, increase maximum

dischage air temperature setting.

26

.

If desired space temperatue is not reached, decrease minimum

discharge air temperature setting.

27

.

If desired space temperature is not reached with heater at high

fire, it may be indersized. Consult equipment manufacturer.

28

.

If temperature reading is incorrect, check items 25, 26 & 27, then

recalibrate if necessary.

K.

Burned out Transfromer. No

Voltage to Amplifier.

25. Check to see if heater is delivering air at maximum discharge air setting.

26. Check to see if heater is delivering air at minimum discharge air setting.

27

.

Check to see if heater is operating at high fire.

28

.

Place thermometer next to T244 or TS244. Compare space temperature

reading with T244 or TD244 dial setting.

25

.

Incorrect maximum discharge air temperature

setting A1044).

26

.

Incorrect minimum discharge air temperature

setting (A1044).

27

.

Insufficient burner capacity.

28

.

Incorrect space temperature calibration.

18

.

Open circuit in TS144.

L

.

Incorrect Space

Temperature.

19

.

Increase inlet pressure if possible or change to larger valve.

Consult Maxitrol about possibility of using special spring to

reduce

pr

essure drop on selected installations.

20

.

See valve adjustments - page 6.

24

.

If proper resistances are not observed, replace modulator head or

repair wiring.

16

.

Remove bottom Plate and inspect valve and seat

17

.

Inspect - plunger should be smooth and clean and operate freely in solenoid sleeve.

18

.

Measure resistance per item 7.