What Fet to replace with

minexplorer

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Well my pimped up tiny wee 6 fet chinese controller has handled the power increase well.Running at 17 -18 amp for long stretches has not given any controller/motor overheating issues.Its climbed the two mile hill to my home a score of times.
So i was surprised when today just a mile into a ride and fairly flat it just stopped working.One fet in the middle has blown .No other damage so i will replace it. My question is it worth upgrading to higher rated ones? The originals, ST p60nf06 if i read correctly are rated at 60amp continous.Perfectly adequate for 17 amps surely.Perhaps it was age fatigue? At least replacing like for like ill only have to do the one. Will i be able to sorce or an equivalent in uk ? .I see em on ebay from china but i need my bike now.Thanks anyone
 
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IRF 4110 or IRF 3077 were always the preferred ones, but be careful, there are a lot of fakes around. buy from a reputable source. I bought some from ebay, which were definitely fake, though they worked OK as battery switches.
 

danielrlee

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Thanks dave ill buy some ,but will i be able to just replace the one,or will they all have to match .Theres a 7th of adifferent type.LM317T.Thanks
The LMT317T is a voltage regulator that powers the controller logic and shouldn't need replacing.

If your battery is less than 60V fully charged, opt for IRFB3077 FETS, since they'll generate less waste heat than IRFB4110's.
 

minexplorer

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The LMT317T is a voltage regulator that powers the controller logic and shouldn't need replacing.

If your battery is less than 60V fully charged, opt for IRFB3077 FETS, since they'll generate less waste heat than IRFB4110's.
Hi danial.Do you have to replace all fets if they are different from the original type.Or can i just replace the single one that popped? Thanks
 

danielrlee

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Hi danial.Do you have to replace all fets if they are different from the original type.Or can i just replace the single one that popped? Thanks
Replacing all six power FETs would give you a cooler running controller, but it should be okay to replace just the failed FET.

ADDITIONAL INFO: Although not relevant for a 6-FET controller, where you have multiple FETs on a single phase leg (9, 12, 15, 18, 24 FET etc) it is safer to replace all of the FETs on the same phase leg (all the highside or all the lowside) with the same kind, so they share current properly.
 

minexplorer

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Replacing all six power FETs would give you a cooler running controller, but it should be okay to replace just the failed FET.
Hi daniel. Do u know suppliers of these irf 3077,4110 fets .Ive looked online and ebay ,amazon .But all the IRF fets im seeing are different from these.Preferably UK so i dont have to wait a month.Thanks
 

anotherkiwi

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