Toshiba VRF IPUD board problem

[Rob123]

Hi All
Hope someone can help.
I have been called out to a VRF with a P22 fault. I ordered up and fitted today the upgraded IPUD board. I did not replace the fan as the winding are ok, aprox 3.1 ohm.
The P22 fault has cleared but the fan wont run and thus goes out on HP.

I have had the same faults on 2 other units over the last 12 months but I have changed the IPUD board and the fan at the same time and hey presto were away.

I suspect the board (the new one has failed) but can someone give me the head up just in case im missing something obvious.

I have been in touch with Toshiba Tech support UK and they say i should change the fan, and the board my be faulty. But the resistance of the fan is within there quoted tolerence.

Any help appreciated

[superswill]

i might be wrong but from memory do you have to add additional heat paste to the IPD's?

[Rob123]

Hi Paul
Yes mate, the upgraded IPDU comes with with a large tube of heatpaste. Which was generously applied..
I should have added that I did have equal voltage across the IPDU output of aprox 57volts fan connected and 82 volts when i ditched the fan.

[daveyboy123]

Ive changed plenty of these, and always changed the fan motor regardless.
Yes there is a heat paste that should be fitted.

Toshiba obviously have a big prob with these.

[billywizz]

Had similar problems and new type IPDU's which are much bigger fixed the problem. Also cleaned off all the old heatsink paste and repasted, I could usually tell which IPDU was faulty of several units by spinning the fan blade the faulty one seems to have a slight drag as if the bearing is gripping which disappears when leads are removed from the IPDU. Many similar posts about this problem before.

[Rob123]

Billywizz...
I have noticed the same thing... the fan does drag... even on the brand new (larger) IPDU.
Im back there Monday morning with another new IPDU and a new fan. I will let you know how it goes.

Rob

[Rob123]

Hi All
Up on a roof at the crack of dawn this morning, replaced Fan IPDU and Fan motor. P22 fault cleared OK but sytems not cooling. Compressor running. Fan runs intermitantly very very slowly. Suspect pressure sensor maybe ?