Newage SX-421 AVR connections 1

[ScottyUK]

Wonder if one of the LV generator gurus might lend a hand?

I have a Newage tail end connected in series star configured for 415V / 50Hz and the SX-421 AVR is tapped on the mid-point of the series stator windings at 208V.
The SX-421 has independent excitation power and voltage sensing. One set is on terminals P2/P3/P4 and the other is on terminals 6/7/8. The utterly useless manual doesn't list the pin-outs for the AVR.

As delivered both power and sensing are connected to the mid-point of the series stator windings. I want to sense the voltage at a remote point from the set, but leave the AVR power fed from the stator mid-point as it is currently configured. I anticipate using matching VTs to step the voltage down to 208/120V to suit the AVR. This should be possible I think, but I need to know which group are the sense terminals. If there are any other flaws in the scheme please shout up.

 

[catserveng]

An MX321 has the same terminal layout as an SX421, here is a wiring diagram for a 321, hope it helps.

Mike L.

 

[waross]

Hi Scotty. After an hour with Google I share your pain.
From this link you may be able to deduce some of the connections;

http://powertechengines.com/NewageData/Manual-Stamford-UC224-274-english.pdf

I left most of my generator data in Central America so I'm stuck with Google for now.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[catserveng]

P2,3 and 4 are the power input terminals, 6,7 and 8 are the sensing terminals. Most of my Newage stuff is older, sorry I don't have better info.

Mike L.

 

[ScottyUK]

Thanks gents, that will do nicely. I had guessed from the location of PCB components that P2/P3/P4 were probably the power connections but it would have been awkward to get them wrong. Much appreciate the help.

I do not understand the secrecy around Newage AVRs. What the heck is wrong with publishing the connections in the manual? Total contrast to Woodward whose governor is on the engine: ten seconds with Google and you have the answer.

 

[waross]

lps Mike

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[catserveng]

Scotty,

Several years ago I got the opportunity to ask a Newage Service Engineer that question, we had a job with CAT engines that has specified Newage tailends, the generators were specified "bare" with the AVR's shipped loose, so the drawings shipped with the generators didn't have any of the AVR connections, when the switchgear company asked for the AVR connections we spent days trying to get answers. In discussing it with the engineer at startup, he said company policy was to supplied "engineered solutions" and that they didn't intend to supply AVR's outside of their generators. They were also pretty put out when we wanted remote mounted AVR's and to use Woodward controls to control power factor, in the end it all worked out, but certainly was an exercise that didn't seem worth it.

Big contrast to Basler, maybe because they supply for OEM's, and the service/retrofit markets?

Regards, Mike L.

 

[ScottyUK]

Thanks for the insight Mike.

I'm about ready to throw the damned thing in the skip and just install an AVR where I have proper documentation and where the manufacturer is helpful to their customers instead of the opposite. It is purely down to me being pig-headed and stubborn that I want to make this work.

Newage have plummented in my estimation due to their policy over documentation. If the SX-421 ever breaks it will be replaced by something from another manufacturer. Thankfully the manufacturers of big sets tend to be more forthcoming with information, I'm not used to being treated like this.