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240v/120v transformer #15418
10/17/02 07:40 PM
10/17/02 07:40 PM
moe707  Offline OP
Junior Member
Joined: Sep 2002
Posts: 3
Bay City, MI, USA
Today, we had a transformer on one of the punch presses explode. The press was not running but we had the panel disconnect switch on only. No other controls were on.
Is this normal for the transformers to explode with time on their own? or do we have an underlaying problem that may cause the same again. The press control panel was wired three years ago.

Thanks for the reply

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Re: 240v/120v transformer #15419
10/17/02 07:52 PM
10/17/02 07:52 PM
HotLine1  Offline

Joined: Apr 2002
Posts: 6,917
Brick, NJ USA
Since the disconnect was "on" apparently the transformer was energized. Are you refering to a "Control transformer"?? Was the transformer primary protected by the correct fuses?? Was the secondary protected by the correctfuses??? Was there any evidence of overloading, overheating prior to the exp??
The usual "destruction" I have encountered is the primary or secondary windings either "short" or "open". The "short" scenario can be rather destructive without primary and/or secondary protection.

Re: 240v/120v transformer #15420
10/17/02 08:07 PM
10/17/02 08:07 PM
Trainwire  Offline
Joined: Mar 2002
Posts: 360
Double check your input voltage, I have had them let go, though not that violently, after a few years, found out that the input voltage was wrong. The guy before me tapped it one side off of the high leg of a 3 phase panel.

somethin' to check

Re: 240v/120v transformer #15421
10/17/02 08:07 PM
10/17/02 08:07 PM
moe707  Offline OP
Junior Member
Joined: Sep 2002
Posts: 3
Bay City, MI, USA
Hi John:

It is a control transformer. the primary and the secondary are properly fused. The press was not on for the past five days at least. The only thing we had on today is the disconnect. The transformer was the only control energized. All other relays, solenoid valves were off.



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