2. Checking the CRII solenoid valves at the compressor

Option 1 (recommended)

Required tools: clip on ampere meter and permanent magnet coil

  1. The compressor with CRII system for capacitiy control must be in operation.
    Remove solenoid coil with electric connector of the device from both CRII cylinder heads, the compressor is now running with 100% capacity.
    Connect clip on ampere meter to CRII compressor (preferably in the switch cabinet).
  2. Attach permanent magnet coil to one of the CRII solenoid valves.
    ⇨ The compressor must now change its operating noise, and the current consumption must be reduced by 40-50%.
    If the current consumption is reduced and the noise changes, the CRII system is functioning.
    If the current consumption is not reduced, the CRII solenoid valve must be replaced (Link to mounting instructions).
  3. Remove the permanent magnet coil and run the compressor with 100% capacity.
    Repeat step 2 for second CRII solenoid valve at the other cylinder head.
  4. If one of the two CRII systems is still not working after the CRII solenoid valves have been replaced, the respective cylinder head must be exchanged.

 

Option 2

Required tools: Pressure gauge and permanent magnet coil

  1. The compressor with CRII system for capacitiy control must be in operation.
    Remove solenoid coil with electric connector of the device from both CRII cylinder heads, the compressor is now running with 100% capacity.
    Connect manometer to compressor (preferably directly to compressor).
  2. Attach permanent magnet coil to one of the CRII solenoid valves.
    ⇨ The compressor must now change its operating noise, and low and high pressure must change (low pressure increases, high pressure drops).
    Remove permanent magnet coil after approx. 10 seconds.
    The operating noise of the compressor now changes again, and the pressures change in opposite direction.
    If the pressures and the operating noise do not change, the CRII solenoid valve must be replaced (Link to mounting instructions).
  3. Remove the permanent magnet coil and run the compressor with 100% capacity.
    Repeat step 2 for second CRII solenoid valve at the other cylinder head.
  4. If one of the two CRII systems is still not working after the CRII solenoid valves have been replaced, the respective cylinder head must be exchanged.

Changes in low and high pressure depend on load conditions, charge volume, and internal system volume at the low and high pressure sides. Thus, this method is a bit inaccurate and should be applied only if the current consumption cannot be measured.