SQFlex Service Instructions

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4.2.1 Trouble-shooting of a solar-powered system with CU 200 control unit and level switch
All measuring points/terminal designations in the following refer to the CU 200 control unit.
1. Check the system by means of the CU 200
If the CU 200 indicates fault, proceed according to section Trouble-shooting by means of CU 200 on
page 10.
2. Disconnect the pump
• Switch off the pump by pressing the ON/OFF button at the CU 200. The OFF light must be on.
• Disconnect the pump cable from the terminal J2.
3. Check the solar modules
• Measure the voltage and short-circuit current across the terminals (2T1, 4T2).
See electrical connection in Section 1.4.
If the DC voltage or DC current is outside the range, one or more of the solar modules is faulty.
Replace the faulty solar module/s.
4. Check the level switch in the water reservoir
• Disconnect the level switch cable from the terminal J5.
• Measure the disconnected level switch cable with an ohmmeter.
• Turn the level switch upwards => the contact in the level switch is closed. The measured value must
be approx. 0 Ω.
• Turn the level switch downwards => the contact in the level switch is open. The measured value
must be ∞ Ω.
If one of the two values is not correct, the level switch is defective. Replace the level switch.
5. Check the CU 200 control unit
• Let the level switch remain disconnected.
• Measure the voltage and current across the terminals for the pump (J2).
If the values measured differ from the values measured under step 3, the CU 200 is defective.
Replace the CU 200.
6. Check the pump
• Make sure that CU 200 is set to off by pressing ON/OFF button. The OFF light must be on.
• Reconnect the pump cable to the terminal J2.
• Reconnect lewel switch to J5.
the lewel switch must point downwards to send a starting signal to the CU 200.
• Switch on the pump by pressing the ON/OFF button. The on light must be on.
Note that the dry running sensor is covered with water.
If the pump starts, it was stopped due to dry running and has now been reset.
• Wait five minutes.
If the pump does not start, it is defective. Repair or replace the pump.
sqflex_SI_US_WG.book Page 30 Thursday, October 1, 2009 3:27 PM