tripp-lite pr-60 transformer issue

[Donald Henderickx]

I have a trip lite pr60 which seems to operate ok however after about 20 min the transformer core get's very hot (threshold of pain)
hot. I disconnect all secondary leads and powered it with a watt meter in the primary and it indicates it is consuming 70watts of
power. Would this be considered normal? what could be the reason for this shorted turns? ,Hysteresis (sic) loss poor steel
in core? I have removed the mounting hardware thinking there could be field shunting issue. no change.

I do not think there is a fix for this but interested to know if any one has any ideas as to what is causing this.

 

[kellys_eye]

Threshold of pain for temperature (human hand) is around 54C.

Transformers have classifications for heat production (maximums) that START at 105C and go as high as 180-200C......

If your transformer is rated at around 600W (given your PSU is only rated at an INTERMITTENT PEAK output of 60A this seems appropriate for a constant output of 40A) then it getting 'too hot to touch' is pretty normal.

The losses you measure seem to be around 10% - pretty high imho - indicating a pretty poor transformer design/wind OR, potentially, a transformer wound for 50Hz being used at 60Hz (or vice versa).

Either way the system should have thermal shutdown built in - another indicator of good design - so check it out......

 

[duke37]

Sounds as if there is a shorted turn.
If the transformer is saturating, then reducing the voltage with a Variac will drop the power dramatically.

What is the transformer specification, does the supply comply?
110V transformer, 120V supply?

 

[(*steve*)]

The important thing about transformers is that if they are hot on the outside then they're a lot hotter on the inside.

That heat can damage the insulation resulting in an internal short.

 

[Donald Henderickx]

The important thing about transformers is that if they are hot on the outside then they're a lot hotter on the inside.

That heat can damage the insulation resulting in an internal short.

Sounds as if there is a shorted turn.
If the transformer is saturating, then reducing the voltage with a Variac will drop the power dramatically.

What is the transformer specification, does the supply comply?
110V transformer, 120V supply?

Thank you all for your reply to my post. I just checked the ratings on the power supply tag it reads 117 vac My ac
typically runs around 123vac . I am going to try the variac suggestion to see if I observe a marked reduction of power dissipation with reduced input. As to specs tripp lite I believe specs 60 amp cont 80 amp surge. As to kellys-eye
reply the transformer was totally unloaded . I don't know if you noted that.
Thanks to all