Refrigeration fuse

[Firesec]

Hi, I have a Danfoss B35 with a older 102n3030 controller. The 15amp blade fuse on the controller blows as soon as I supply power via the switch. I have eliminated the controller and attachments as the issue as the fuse blows only when the compressor is connected. The compressor is in a nightmare of a spot with limited access therefore I am asking for advice prior to dismantling part of my chart table to get access. Any advice would be appreciated. Cheers.

[flyingfin]

Could be a locked compressor, stick in a 20 amp fuse and see if it spins, fries the bigger fuse or starts to melt the power supply wires

[Firesec]

Update: tried with leads disconnected at compressor and all good. Connected leads to compressor and fuse went. Obviously internals of compressor so out it comes.

[Richard Kollmann]

The compressor is not the problem you need to find a replacement 4 pin module. And make sure the fuse in new module is 10 amps no larger. A mechanical or locked rotor in this type compressor will not cause fuse to blow. Excessive module temperature over time will cause one of the two chopper current reversing transistors in module to short out blowing module fuse.

You will have trouble finding a replacement 4 pin module as Danfoss stopped making them over 20 years ago. Frigoboat, Adler Barbour and a manufacture in the far east did make replacements for a few years. Any of the 4 pin 12 volt modules will operate your unit, Danfoss made ten defferant models of the 4 pin anyone of those will work on your unit. Try WWWRparts.com or look on Ebay for a used one.

[Firesec]

Thanks Richard but you mention excessive nodule temp over time. The module is blowing as soon as the compressor is connected. There is virtually no time for overheating. Cheers
QUOTE=Richard Kollmann;3302649]The compressor is not the problem you need to find a replacement 4 pin module. And make sure the fuse in new module is 10 amps no larger. A mechanical or locked rotor in this type compressor will not cause fuse to blow. Excessive module temperature over time will cause one of the two chopper current reversing transistors in module to short out blowing module fuse.

You will have trouble finding a replacement 4 pin module as Danfoss stopped making them over 20 years ago. Frigoboat, Adler Barbour and a manufacture in the far east did make replacements for a few years. Any of the 4 pin 12 volt modules will operate your unit, Danfoss made ten defferant models of the 4 pin anyone of those will work on your unit. Try WWWRparts.com or look on Ebay for a used one.[/QUOTE]

[Richard Kollmann]

Originally Posted by Firesec

Thanks Richard but you mention excessive nodule temp over time. The module is blowing as soon as the compressor is connected. There is virtually no time for overheating. Cheers
QUOTE=Richard Kollmann;3302649]The compressor is not the problem you need to find a replacement 4 pin module. And make sure the fuse in new module is 10 amps no larger. A mechanical or locked rotor in this type compressor will not cause fuse to blow. Excessive module temperature over time will cause one of the two chopper current reversing transistors in module to short out blowing module fuse.

You will have trouble finding a replacement 4 pin module as Danfoss stopped making them over 20 years ago. Frigoboat, Adler Barbour and a manufacture in the far east did make replacements for a few years. Any of the 4 pin 12 volt modules will operate your unit, Danfoss made ten defferant models of the 4 pin anyone of those will work on your unit. Try WWWRparts.com or look on Ebay for a used one.

[/QUOTE]

The BD2,BD2.5 and BD3 Danfoss compressor pump armatures are not conventional 12 volt motors they are electronic pulse driven by an electronic smart control module.

If failure to attempt to start occurs because of electrical voltage or excessive current the module will switch off current preventing compressor from starting. On your 4 pin unit there will be a chirp sound when module disconnects power to compressor. Earlier overheating caused by heavy loading of compressor is what can caused module to over heat and failure.