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Instructions
In the maintenance PC of the condensing unit, the compressor rotation speed CM1, the suction superheat degree, the indoor unit expansion valve
opening degree, and the oil return control status are selected, and whether the expansion valve opening degree is opened by the oil return or not, the oil
return control is normally completed (10 minutes end or end in time due to low overheat), and the oil return control status is confirmed.
11.3. Operation check of protective device
Confirm that, if a protective device trips, an alarm is released and the unit stops by the error stop.
Out of various protective devices for the condensing unit, confirm here, as a representative example, if the error stop occurs when the thermistor error is
raised forcibly.
1. Disconnect CNTH1 connector (Gas cooler temperature Tho-G1, G2 thermistor).
2. Turn on the power supply. (It can be confirmed for 20 seconds only at 10 minutes after starting operation.)
3. Confirm that it stops approx. 5 seconds later. (Alarm code "E-37" is displayed.)
4. Reinsert the removed CNTH1 connector as it was.
5. Reset the alarm code as follows.
• Pressing SW8, SW9, change the 7-segment display to "P20", and press SW7 for 3 seconds or more.
• Change from "0" to "1" with SW8.
The alarm code is reset.
If the external input P08 (CNS3) is set at "3: Error reset", it can be reset also externally. Make sure, however, to check the error code and remove the cause
of error, before resetting.
6. Confirm that the operation restarts. (Alarm code "E-37" extinguishes.)
7. Clear the history of alarm code with "C96" and SW7
8. By the low pressure cut or turning "OFF" the breaker, end the operation confirmation (stop of condensing unit).
12 – Check with running unit
• Check the fan rotation direction. Air must flow from the condenser towards the fan.
• Check current draw and voltage.
• Check suction superheat to reduce risk of slugging.
• Respect the operating limits.
• Check all tubes for abnormal vibration. Movements in excess of 1.5 mm require corrective measures such as tube brackets.
• When needed, additional refrigerant in liquid phase may be added in the low-pressure side as far as possible from the compressor. The compressor must be operating
during this process.
• Do not overcharge the system.
• Follow the local regulations for restoring the refrigerant from unit.
• Never release refrigerant to atmosphere.
• Before leaving the installation site, carry out a general installation inspection regarding cleanliness, noise and leak detection.
• Record type and amount of refrigerant charge as well as operating conditions as a reference for future inspections.
13 – Guidance at delivery
When delivering the product to personnel who control daily use, explain about following items.
• Explain and instruct sufficiently about cautions as described on page 2 to 5 Safety precautions.
• Produce a check list for test run. Hand it over with explanation on the procedures of daily control of operation.
• Explain about ways of regular maintenance.
• Explain about measures to respond to activation of protective devices or accidental failure on operation. Inform the contact desk for such occasion.
• Explain the need to have professional after-sale services, and recommend to close the maintenance service (onerous) agreement.
14 – Maintenance
Internal pressure and surface temperature are dangerous and may cause permanent injury. Maintenance operators and installers require
appropriate skills and tools. Tubing temperature may exceed 100 °C and can cause severe burns.
Ensure that periodic service inspections to ensure system reliability and as required by local regulations are performed.
To prevent system related problems, following periodic maintenance is recommended:
• Verify that safety devices are operational and properly set.
• Ensure that the system is leak tight.
• Check the compressor current draw.
• Confirm that the system is operating in a way consistent with previous maintenance records and ambient conditions.
• Check that all electrical connections are still adequately fastened.
• Keep the unit clean and verify the absence of rust and oxidation on the unit components, tubes and electrical connections.
© Danfoss | Climate Solutions | 2023.02 | LCA012A024
118A5495A - AN405821998738en-000102 | 39
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