TROUBLESHOOTING GUIDE
Series 14 Discharge Temperature Control continued |
| Reproduced with permission from Maxitrol® Company | ||||||
Symptom |
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| Possible Cause |
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| Field Test |
| Remedy |
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H. continued |
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| 4. | With test resistor | 4. | If erratic or unstable D.C. |
4. | Faulty Amplifier or | |||||||
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| erratic voltage supply. |
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| connected (per item H2) |
| voltages are obtained |
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| and TD114 locally |
| throughout the modulating |
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| connected (per item H3) |
| range, the amplifier may be |
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| turn TD114 selector dial |
| assumed faulty. Replace. If |
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| through entire modulating |
| erratic operation is noted |
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| range. Observe D.C. |
| only over a small range of |
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| voltage across modulator |
| 2 or 3 volts, the voltage |
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| terminals. |
| sources may contain surges. |
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| Consult factory for other |
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| solutions. |
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I. Incorrect Discharge |
| 1. | Inlet Air sensor is used. |
| 1. | Inlet Air Sensor changes | 1. | Sensed temperature will |
Air Temperature |
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| 1° or each 3.5°, 5° or 8° |
| vary from TD114 dial |
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| outside temperature change |
| settings. This is intentional. |
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| from 60° (predetermined - |
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| turndown varies with |
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| model used). |
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| 2. | Incorrect wiring. |
| 2. | Check wiring diagram for | 2. | Correct wiring. |
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| heater. |
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| 3. | System out of |
| 3. | Sensed temperature | 3. | See calibration procedure. |
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| calibration. |
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| (thermometer next to |
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| TS114) does not correspond |
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| to TD114 setting. |
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| 4. | Improper TS114 |
| 4. | Sensed temperature (thermo- | 4. | Move TS114 to location |
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| location. |
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| meter next to TS114) does |
| where average representative |
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| not represent average |
| temperature can be sensed. |
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| discharge air temperature. |
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| 5. | Room Override |
| 5. | Remove Override | 5. | TD114 dial setting, then check |
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| Thermostat circuit |
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| Thermostat lead from |
| thermostat setting and/or |
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| closed. |
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| terminal 2 of TD114. |
| check wiring for shorts. |
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J. Burned out |
| 1. | Short circuit in |
| 1. | Measure resistance across | 1. | Replace modulator head if |
Transformer. |
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| modulator coil. |
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| modulator terminals with |
| less than 40 ohms. |
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| red lead wires disconnected. |
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| 2. | Short circuit |
| 2. | Inspect wiring. | 2. | Correct wiring if short |
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| between amplifier |
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| is found. |
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| and modulator valve. |
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K. Discharge Air |
| 1. | Override Temperature |
| 1. | Check “Override Tempera- | 1. | Reset to correct temperature. |
Temperature too |
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| setting is too low. |
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| ture Selector” of TD114. |
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low when TS115 |
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is operative. |
| 2. | Burner capacity may be |
| 2. | Check for high fire (Maxitrol | 2. | If on high fire, control can |
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| insufficient. |
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| manifold pressure specified |
| do no more. Heater unable |
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| for heater). |
| to furnish additional heat to |
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| raise temperature. |
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L. Automatic Control |
| 1. | Faulty automatic |
| 1. | Read voltage across auto | 1. | Replace automatic control |
Valve will not open |
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| control valve. |
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| valve terminals. If 24V AC, |
| valve. |
despite full range of |
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| valve is faulty. |
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modulating voltage |
| 2. | Open wire to automatic |
| 2. | Read voltage across | 2. | Correct wiring. |
at terminals 3 & 4. |
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| valve. |
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| terminals 5 & 6. If 24V AC, |
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| check for open circuit to |
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| automatic valve. |
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13
