Unknown Transformer

[Scra99tch]

I do know the make which is an Acme transformer.

But how would I go about testing it without causing too much damage to soft tissue. H1,H2,H3 are all connected to winding #3 if I understand correctly.

It was given to me with a machine which has 380V motors ion it. Supposedly run from 220V 3 PH power supply. This last part I am not entirely sure of though.

X1,X2,X3 and Ground RED,BLACK,BLUE,GREEN) are from the original supply source on the primary coil.

Could it be #71 page 40 of this manual just run backwards as this shows X1,X2,X3 on # 3 instead of how its wired now on HQ,H2,H3 on #3?

https://hubbellcdn.com/ohwassets/HCI/Acme_Electric/Literature/SECTION-1.pdf

 

[FOMOGO]

I think you may need a coyote to check that one out for you. Mike

 

[JimDawson]

Can you post a picture? Is there a data tag on the transformer?

You could apply maybe like 12VAC from a doorbell transformer and see what voltage comes out the other side, a nice safe low energy method of testing. This would give you the winding ratio.

If the motors are 380V and the machine was running on 240V then it is quite possible that the 240V was connected to the ''X'' side of the transformer to get 380V out of the ''H'' side. Most transformers can be operated in either direction; step up, or step down.

 

[Scra99tch]

The data tag is smudged beyond recognition. It looks like design B on page 35 on my link. I will try and take some measurements of the box and weight.

I have a variac I could use to supply a low voltage possibly.

Is there a general multiplier I would use if I supply 12V do I get a factor of 2.1... out of other side?

 

[JimDawson]

Winding ratio = voltage in/voltage out

so 240/380 = 1:0.6315 (step down) or 1: (1/0.6315) = 1:1.5833 step up

So if the above is correct 12VAC in would = 19VAC out or 7.58VAC out depending on the direction it is connected.

 

[Scra99tch]

Awesome thank you. I'll keep this thread posted.

I'll be powering it with a rotary phase converter.

 

[tq60]

Winding ratio = voltage in/voltage out

so 240/380 = 1:0.6315 (step down) or 1: (1/0.6315) = 1:1.5833 step up

So if the above is correct 12VAC in would = 19VAC out or 7.58VAC out depending on the direction it is connected.

Be careful and measure with same voltmeter both sides.

A 12 vac wall wart is usually only that voltage under some not clear load.

Connect the device then measure while powered on and connected.

Write reading down then measure opposite side and now you have a clue.

Find a light bulb or other device as load to attach to output.

Remember the current capability of the wall wart is effected opposite that of voltage.

If voltage doubles then current less than 1/2.

After measurements made calculate ratio.

Reverse the calculation to determine what would be output if connections reversed then reverse and measure to confirm.

Using 12 to 24 volt wall warts allow for low voltage and current so easy to test safely.

Sent from my SAMSUNG-SM-G930A using Tapatalk

 

[markba633csi]

Remember most wall warts are dc but some ac ones exist- transformers only work with ac. Variacs are ac, but they are not isolated- be careful of shock hazard. Even if the Variac is set for a low voltage output like 12V you still can have a 120 volt potential from the output leads to ground. Look up "autotransformer" to learn more
-Mark