Raychem EM4-CW Installations- Und Betriebshandbuch Seite 20

Problem B: residual current device trips
Probable causes
Excessive moisture in junction box
Earth fault at:
• connection
• damaged heating cable
Leakage current too high:
power cable or heating cable too long
Contactor bouncing
Voltage spikes in power supply network
Defective rcd
Problem C: Ice/snow not melting
Probable causes
Loss of supply current due to over-current Follow procedures outlined in A and B
or residual current device operating.
Loss of supply cable continuity
Incorrect setting or operation of
system controls
Incorrect contactor sizing or damaged
contactor
Problem D: Ice/snow begins to melt, but system turns off too soon
Probable causes
Incorrect setting or operation of system
controls.
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Correction
Dry out and check seal; replace if
necessary. Perform an insulation
resistance test.
Locate and rectify the fault and reset or
replace rcd.
Correct problem and re-design.
Replace with higher quality contactor
Reset rcd. If condition persists, use
clean power supply.
Replace
Correction
above.
Locate and rectify fault.
Repair system controls or set system
controls correctly
Rectify
Correction
Repair system control unit or set system
controls correctly.