C O M P R E S S O R S
Technical information
Fault Location on
PL, TL, NL, FR Compressors
R E F R I G E R A T I O N A N D A I R C O N D I T I O N I N G
General |
This Hermetic Note is directed especially to the service network, for house- |
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hold appliances and similar. For detailed information on compressors see the |
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data sheets. |
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Compressors type PL, TL, NL, FR and partly SC are equipped with a PTC |
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starting device (fig. 1) or a relay and start capacitor (fig. 2). The motor protector |
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is built into the windings. |
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In the event of a start failure, with a cold compressor, up to 15 minutes can |
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elapse before the protector cuts out the compressor. |
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When the protector cuts out and the compressor is warm, it can take up to 1 |
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hour before the protector cuts in the compressor again. |
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The compressor must not be started without the electrical equipment. |
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Fig. 1: PTC starting device |
Fig. 2: Starting relay |
Fault location |
Before beginning systematic fault location, a good rule is to cut the supply |
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voltage for at least 5 minutes. This ensures that the PTC starting device has |
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cooled off and is ready for start. |
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A voltage drop or blackout within the first minutes of a pull down of the |
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appliance with cold compressor, can lead to an interlocking situation. A |
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compressor with PTC can not start at non equalized pressure and the PTC |
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does not cool down so fast. It can take more than 1 hour until the appliance |
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then operates normally again. |
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Electrical compressor |
To avoid unneccessary protector operation and consequent waiting time, it is |
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quick check |
important to carry out fault location in the sequence given below. Tests are |
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made according to desriptions on following page. |
• Remove electrical equipment
• Check electrical connection between main and start pins of compressor terminal
• Check electrical connection between main and common pins of compressor terminal
• Replace compressor, if above connection checks failed
• Else, replace electrical equipment
If the compressor still does not operate, most probably it is no electrical compressor failure. For more detailed fault location, see the tables.