Teco inverter 7300CV

[keland_uk]

Teco inverter 7300CV. I have been asked to look at one of these where I think a Power thermistor on the i/p has burnt out. Photo 1. It looks like 1 20SP UEI thermistor, but Ohmage has been destroyed. Anyone any ideas how to identify blown device, assuming it is a thermistor in the 1st place. I can't find any circuit diagrams for this inverter anywhere.

Any help appreciated.

Best Regards
Chris

[fzabkar]

It's definitely an NTC inrush current limiter.

https://m.media-amazon.com/images/I/818qjMHQldL._AC_UF894,1000_QL80_.jpg
https://images.tokopedia.net/img/cache/500-square/product-1/2020/9/29/7285560/7285560_3f61c650-2d7c-4aa9-91ba-ecb3cfcfb695_1449_1449.jpg
https://ae01.alicdn.com/kf/HTB1kRLtKbSYBuNjSspiq6xNzpXai/New-and-original-MF72-5D20-NTC-20SP005-20SP-thermistor.jpg

Is the device bypassed by a relay after the power rail has come up to spec? If so, check that the corresponding area is working properly, otherwise the burnt NTC may just be a symptom of the real problem.

[keland_uk]

Thank you. any Idea on value tho. those you showed seem to be 2.5/20 and 5 ohm respectively.

I found a picture of a different board by Teco, also marked as TH201, NTC marked 20SP 012 but the schematic the guy had done seemed to have a 15 Ohm NTC. Of course different cct