MemberApril 29, 2021 at 10:20 am
Hi All – Have a Manitowoc ID-1402 (air cooled, R404a), laid up for winter and recently cleaned/put back into service, has me scratching my head. On startup, machine made around 10 drops of ice in normal time (~11 mins/drop), then powered off mid cycle, as in lost all power to control board, entire machine goes dark at once. After a few minutes, cycled power at the breaker and machine powered back up, restarted as normal, but continues to power off mid-cycle every time. Condenser has been cleaned and fan cycles normally, error log on machine only shows the power loss events each time they occur, no other errors.
First thought was HPCO or similar, but would expect the control board to log that error instead of dump all power to the machine. Have verified power to the unit is not dropping out, have replaced breaker out of caution (weak contact, etc.), and verified no internal shorts in the unit. Ran separate temporary power directly to the service panel to rule out premise wiring, same behavior. Compressor amps when running are normal, evap is cooling as expected. Machine cycles into freeze, starts water flow and gets to about 1/16″ of ice starting to form on grids, then goes dark.
Wanted to bounce it off the experts here to see if there is anything obvious I may be missing with the power loss symptoms, or any areas to focus on. The service manual troubleshooting guide covers a bunch of scenarios, but doesn’t mention complete power loss like this with no codes logged. Thanks!
MemberApril 29, 2021 at 5:09 pm
You never said what power you have, single or 3 phase?
Regardless, It sounds like a intermittent open of the line or control transformer. On the control board lower right side is a 9 pin plug for the high voltage side. Right above it is a 7 amp fuse for the transformer. I suspect that in storage you experienced some corrosion of either the plug pins or the fuse in the fuse holder. In the plug, the top right (L1) and the one below it (L2) are the line circuit. The other thing is the display plug just below the temp sensor plugs. I would monitor the line voltage in that plug to narrow down if it is opening prior to the control board or in the plug connections. Also check the compressor contactor line side. That’s where they pull the power off for the control circuit. Spade connectors are notorious for this in a high load like that machines compressor has.
MemberApril 29, 2021 at 5:46 pm
Thanks for the info fixbear – this is a single phase machine. I had pulled and checked the control board fuse, but haven’t tried monitoring where the voltage is dropping out or the display plug. Will do a general contact cleaning on all of the control connections and set up probes to see who is losing power first. Appreciate the help!
MemberMay 5, 2021 at 10:10 am
Wanted to post a quick follow-up to this one after getting back to the unit. Confirmed that power to the control board at the 9-pin Molex connector is consistent even after the machine powers off, and that the control board fuse is good as well. Checked/cleaned all other connections, all were in good shape to start with. Problems are unfortunately pointing me towards a control board failure, have the board removed now for further testing of transformer and associated components. The on-machine control board diagnostic check shows as passed, but it’s still cutting out at random times. For example, running the relay test mode where all relays activate – sometimes you can initiate this mode and it will run fine. Other times it will initialize all relays/components correctly, but within 5-10 seconds machine power will cut out again, so seems like the CB is losing power somewhere on the board itself. Will reply here with any updates after troubleshooting the CB more.
FYI – Control board is the Blue (Firmware Rev 4) version, P/N 000009035
Thanks again for the help!
MemberMay 5, 2021 at 7:48 pm
That sounds like either a bad solder joint on the board, or a transistor/chip overheating.
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