Waeco BD35 will only run when tilted

[ajrw]

My Waeco portable freezer CF40 with a BD35F compressor will only run when the freezer box is tilted more than 45 degrees from horizontal (any direction and upside down).

When in normal horizontal mode the compressor stops but the fan continues to run. Voltage at controller is stable at 12.4v (boat battery 13.5v) whether on mains 240 or 12v power and when rnning and stopped.

Disconnection of fan makes no difference. There are no red error flashes. The compressor just stops running but is perefect and freezing when tilted.

Are there any sensors that could have failed to cause this. Will I get a lubrication problem if run tilted.

Any ideas welcome to explain this
Tony

[a64pilot]

Check your electrical connections really well, especially those Spade connectors, BD should in my opinion not have used them, they loosen easily and do flaky things.

[senormechanico]

I absolutely HATE 1/4" spade connectors and removed every single one of them from my boat, replacing them with proper SS terminal strips.
For connectors which may need to be occasionally disconnected, I like these trailer type connectors.

They are available in various gauges of wire and pin numbers.

[a64pilot]

Yeah, but the BD controller has a row of male spade connectors, which pretty much means your putting females on the wiring.
I’d be suspicious of the main power wires.

[senormechanico]

I didn't go THAT far. I meant all the boat's original wiring harness connectors.
I put one of those ten gauge trailer connectors on our brand new freezer before even putting it on our boat, replacing the ciggy plug connector.

[DeepFrz]

Voltage at controller is stable at 12.4v (boat battery 13.5v) whether on mains 240 or 12v power and when rnning and stopped.

I think this is your problem right there.

[ajrw]

Thanks for suggestions and will now clean spades.


It is suspicious that the voltage drop of 1.1v when compressor is running and quite normal in my opinion but remains the same when the compressor stops running but fan still running.


I will report back

[Richard Kollmann]

Originally Posted by ajrw

My Waeco portable freezer CF40 with a BD35F compressor will only run when the freezer box is tilted more than 45 degrees from horizontal (any direction and upside down).

When in normal horizontal mode the compressor stops but the fan continues to run. Voltage at controller is stable at 12.4v (boat battery 13.5v) whether on mains 240 or 12v power and when rnning and stopped.

Disconnection of fan makes no difference. There are no red error flashes. The compressor just stops running but is perefect and freezing when tilted.

Are there any sensors that could have failed to cause this. Will I get a lubrication problem if run tilted.

Any ideas welcome to explain this
Tony

Problem is in the wiring voltage drop at compressor start between 13 volt battery and 12.5 volts at compressor electronic controller. This condition will trigger a low voltage safety protection shutoff spike below 10 volts that can not be seen with a volt meter. Without this protection compressor could be damaged.

[a64pilot]

I do believe it’s a voltage issue and think he need to run a large gauge wire temporarily to validate that.

However I’m stuck on why it will run on it’s side and not up right and apparently that’s repeatable, not a one time event.
I was theorizing that laid over pulled the wire right enough to make a better connection.

Try talking both ends of the wire loose and cleaning the connections, you need to solve that voltage drop issue, voltage drop indicates a high resistance connection of course and that can certainly indicate exactly what Richard is saying.
Unfortunately I’m of the opinion that the voltage drop during start can be of such a short duration that a multi meter may not capture it, so that easy check may not show the problem.

[Redline452]

perhaps on its side the refrigerant in the compressor isn't pooling in the same place, and places less of a strain on the pump at the instant it tries to start, leading to the voltage-dropout issue?

[Cadence]

Don't forget the neg. connections. You might want to measure voltage at the unit back to battery neg. terminal. and read between the neg. at the unit and the battery pos. post.
How on earth did you determine that it worked at 45 deg. in any direction?

[a64pilot]

Originally Posted by Redline452

perhaps on its side the refrigerant in the compressor isn't pooling in the same place, and places less of a strain on the pump at the instant it tries to start, leading to the voltage-dropout issue?

If it’s trying to compress a liquid, it does have real issues, that’s called slugging and I think by design isn’t an issue with these compressors, but am not sure on that.
Larger as in house compressors are often heated to prevent liquid condensing in the compressor case, but trying to compress a liquid is very hard on a compressor, at least a piston type anyway, maybe a scroll handles it better?

[ajrw]

Thank you all for suggestions. It was indeed a voltage issue caused by the fan. I cleaned all the spade ends to no avail. just as last ditch trial, I disconnected the internal 4" fan and attached a spare 6" on the outside casing and hooked this up to fan + and - on the controller and wham bam it worked when horizontal. I have not been able to remove the old 4" fan yet but thinking that the bearing has gone and causing excessive current draw and voltage drop when horizontal but not tilted. The old fan seems to work OK visually but a most peculier and repeatable fault. As your experience shows its usually a voltage problem but I just did not believe it. Now for the tricky job replacing the old fan.

[Redline452]

Thanks for the followup - makes sense, and not something obvious.


I had something similar happen this summer - the engine compartment blower, normally fairly noisy, became quieter... then stopped. Pulling it out and testing it in open air to rule out any wiring issue, it worked perfectly - when vertical. Horizontally, nothing.



The interesting thing was that rotating the blower assembly from vertical to horizontal produced a perfectly linear speed control, from 100% to stopped and back, very repeatably (I even have video). Of course, when installed it had to work horizontally, not vertically, so it was useless. A little poking revealed much carbon dust from what was left of the brushes, so the motor was toast. But I'd never seen one fail so... gracefully?

[ajrw]

Thanks for that. As you say it just gracefully cut out. At least I know I'm not going mad.