Author Topic: 7.5 st head update UPDATE  (Read 655 times)

32 coupe

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7.5 st head update UPDATE
« on: November 11, 2017, 04:12:07 PM »
I received the 230 avr from Tom.... here are my new numbers :

no load
237 volts....118.7 each leg


10 amp load on both legs
238 volts
109.7 on 1 leg
135 on the other

10 amp load on 1 leg
124 on 1 leg
116 on the other

The growl is much worse with an unbalanced load.
If I wanted to use it for a dedicated 230 or 115 gen set it would
probibly be fine. To use it for a 230/115 load it looks to be too much
of a spread for anything with a "sensitive" load.

I plan to call Tom again on monday to see what he has to say.

This only reinforces my decision to purchase the "stamford clone" next.

Again, I will post results.

Thanks for your time,
Gary


Metro 6/1 turning a ST 7.5 KW gen head
Changfa 1115 turning a ST 15 KW gen head
Ashwamegh 2/25
John Deere 110 TBL
New Holland TC 30

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BruceM

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Re: 7.5 st head update UPDATE
« Reply #1 on: December 05, 2017, 05:07:34 AM »
It seems the stator windings are another variable in the China ST vs typical Rajkot QC competition.  (A race to the bottom.)

No way should you be seeing so much voltage variation for the modest load you tested at between the two sets of windings when loading both legs perfectly evenly, and using a 230V AVR off the mains for excitation so no load imbalance there.  It would seem that one stator winding has a problem.




glort

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Re: 7.5 st head update UPDATE
« Reply #2 on: December 05, 2017, 11:19:02 AM »

Definitely think I'll go for a 3 phase STC unit at least or the brush less Stamford type, also in 3 phase.

Bit over new stuff I have to fix before I use it. Rather pay the money up front and have something I can enjoy and be satisfied with.