And here I've been sitting with the reverse of your dilemma. I have a 3 phase 380V 2-speed Bench drill that I want to run on 220V single phase. Have been reading about all sorts of cowboy hacks with capacitors, static and rotary phase convertors but seemingly the only cost efecetive solution...
If the Trafo is small enough and has an OLTC then open it up and take a look... to heck with wasting time on the DGA unless you have a testing lab up the street. Otherwise if its new and under guarantee, get on the blower to the manufacturers and get them to address the issue.
The circulating currents between 2 or more paralleled trafos on different taps tend to cause additional heat build up over and above that of normal loading and effectively reduces the usable capacity of the trafo.
We have a substation with 4 x 2,5MVA 30//6,6kV paralleled trafos of which 1 is 2...
The smaller palm also has 3 times the thickness of the larger palm... 45mm vs 15. This would also have an effect on the amount of warping that would occur away from the bolting areas especially if using alluminium.
Jointing compound is a must and definitley correct torque values and correct...
That is how we were taught too although I had a different opnion especially with most of our pole mounted distribution trafos had the surge arrestor mounts below the main bushings. Droppers go to the arrestors first then only to the bushings.
On querying this with one of our company engineers...
I repair domestic appliances & power tools as a side line (excuse for a hobby). The power tools are sometimes an issue with suspected armature faults and the lack of a growler to test for shorts etc. Has anyone built their own growler or is it a project not worth the effort? Should I rather try...
Thanks Scotty, I'll search the Dahlander connection, haven't heard of it before but never too old to learn something new.
We have considered the VSD option on a new motor in terms of cost vs effort vs downtime on fixing the old. This unit has been rewound by our local motor rewind shop somewhere...
@majesus, sorry to branch off on your topic. That's Canada... fair enough. I was wondering as we have a substation in Southern Africa where the zig-zags were connected as you depict with interlocking to the main transformer LV busbar CB then the wiseguys with thick glasses came and insisted the...
Greetings all
I have a 380VAC 3phase, 3 speed motor electric motor with 9 leads emminating from the stator. Power rating +/- 1Hp, 2,4 & 8 poles listed on the nameplate with speeds of 2800, 1400 & 700rpm respectively. The motor has burnt and now there is much speculation in the shop as to how...
Curious... Shouldn't the zig-zag on the 600V (Delta) side be connected directly to the main transformer without CB's and not from the bus as a "feeder"?
