How to troubleshoot fan power supply faults on an ACRC, ACRD, and ACSC.
All 300mm Units
All Product models, all serial numbers
Power Supply fault
Should you need to troubleshoot the 48V power supply for a failure, please know, the Fan Power Supply Fault occurs when the power supply output is at least 1 amp less than the output of all of the other power supplies in the unit. This occurs when the fans are commanded on and the power supply output is less than 200mA. If a single power supply fails, the controller will limit the maximum fan speed to 70%. The location of the fan power supplies differ depending on the model#. When a power supply fails you will need to know this location based on the unit in question. Also, the alarm may report Left Fan Power Supply Fault or Right Power Supply Fault on an ACRC or ACSC. Whereas, on an ACRD the power supply failure will read Upper or Lower Fan Power Supply Fault.
Rectifier LED indicators:
● Over-voltage LED: When red, rectifier DC output voltage is above 57 Vdc (must be powered down to reset)
● Current limit LED: When red, rectifier is at current limit
● Input healthy LED: When green, AC power is present
● Output healthy LED: When green, rectifier DC output voltage is 39.5-59.5 Vdc (set for 48 Vdc nominal)
The new power supplies ship in all ACRC1xx YK0844xxxxxx, ACSC100/101 YK0815xxxxxx, and all ACRDs.
A new DC power supply from a new manufacturer has been introduced into production, replacing the previous power supply. The new part has a unique part number (W920-0082) and can be visually identified as shown and noted later in this bulletin.
The new part is removed and installed in the same manner as before.
The only requirement is that the old and new design power supplies are not to be intermixed in the same unit. That is, use in pairs of old or new, but not one of each.
Use the schematics to help you troubleshoot the failures if reseating and swapping the power supplies fail indicating the failure is beyond the power supply.
#2 Standard or Phillips screwdriver; T30 Torx screwdriver [ACSC only]
The individual power supplies can be replaced without removing power from the unit. For safety reasons, remove power whenever possible. If you must swap power supplies while the unit is receiving power, take appropriate safety precautions to avoid moving parts and live electrical components.
Replacement (ACSC) will need T30 Torx screwdriver [ACSC only]
Caution: Two different power supplies are available for this unit. One type has holes in the metal faceplate in front of the fan, as shown. The other type has a wire guard over the fan. Either type will work, but both power supplies must be the same, or improper operation will result.
ACRD - Located on the rear slide tray [upper and lower power supply]
ACRC - Located in the rear bottom
Located in the front behind the display and front panel