Need to find a generic AVR for a 13KV generator 1

[takoateli]

I have a 13KW "Yamaha" generator which was sold in Venezuela for which we can't get parts or support.

The AVR blew failed and we need to get a new one.

I believe that since it's a six wire alternator it should be easy to get a generic AVR that will work with this unit. I'm curious to know if the pros here agree.

Thanks!

Sorry if this isn't the right venue for this kind of question.

Greg

 

[pwrengrds]

Yes it should be straight forward to replace it. The trick is going to be figuring out exactly what to buy and how to wire it up. Basler sells them as well as many others. I would recommend you have a chat with their tech support if you don't know how to figure it out.

 

[takoateli]

Thanks! Happily we have an identical generator here that works, so I can measure the sense voltage to the AVR and know exactly what I need.

The AVR senses across two of the three phase windings, but the windings have a tap for the AVR so the AVR doesn't see the full voltage from the two phases.

Greg

 

[waross]

If you can get a direct replacement no problem.
For a generic replacement I would want to know what connects externally to terminals Go and Gu coming from terminals 4 and 200 on the AVR. If they are not used, you may use a generic replacement with 220 Volt sensing. Check the resistance of the exciter field. Generic replacement AVRs often specify a minimum load resistance. 16 Ohms was common. As long as the resistance of the exciter winding is above the spec of a generic replacement it should work.
This is the resistance that terminals F+ and F- see.

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

 

[takoateli]

Thanks once again for your help!

Unfortunately a direct replacement is not possible. A big problem we have in this country is that people import and sell items for which there is no supply chain for spare parts and the seller has no intention of providing spare parts. This is yet one more example.

To make matters even worse many items which are sold here are strange models which are not sold in the US. So even though the item might be an authentic name brand product, such as Yamaha, Honda etc. the items are not in the US representatives database, so the items can't be looked up to find even a cross-reference.

Often when I Google the model numbers of equipment sold here often the only search results are in Russian or an Asian language. I think many times the items sold here are things which don't meet US or European emissions standards so that's why the items are not listed in US databases.

All let's say we've exhausted all resources and can't find a direct replacement for the AVR. We've been told that even though the generator is branded Yamaha it's really a Kubota, but even that was no help. So it's going to have to be a generic replacement.

Happily there's nothing else connected to the external terminals you mentioned above (Go and Gu, terminals four and 200). Those connections come out to a terminal block but nothing is connected to it

I'm hoping that just the DC resistance of the exciter is good enough. I don't have equipment to check the AC resistance. Is DC resistance good enough?

Thanks again!
Greg

 

[ScottyUK]

You could try a little company in the UK called Roper Electronics. Thay helped me out with a replacement AVR for a generator which belongs in a museum. Actually it is in a museum, the one I call 'the plant', ha-ha. They have a pretty big selection of types, although probably geared toward slightly larger machines.

Do you have enough equipment to be able to measure the field current and voltage required to raise nominal voltage with the main terminals open circuit? A multimeter and either a variable DC supply or a series resistance would probably suffice. As a crude rule-of-thumb, at full load the AVR will need to deliver between 2x and 3x that value.

----------------------------------

If we learn from our mistakes I'm getting a great education!

 

[takoateli]

Thanks Scotty!

I have a RadioShack DVM that can measure AC current up to 10A, so I should be able to make the measurement you suggest. When you say "main terminals open" you mean with no load on the generator correct? You don't mean I need to disconnect any of the AVR's leads right?

Greg

 

[waross]

I think this is a 13 KW, not 13 KV. Just measure the resistance across the leads that normally connect to F- and F+, DC resistance is all.
You can spin the machine up with a 12 Volt battery connected to the field. Measure the output voltage and do a simple ratio to determine the field voltage needed to generate rated voltage. The field voltage under load will be at least double the no-load voltage. I will be surprised if any off the shelf small AVR is not suitable.

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

 

[IBRCAN]

The DC resistance of the exciter field winding is what is needed. The output of the regulator through the exciter is DC. You need to use a DC ammeter to measure field current. I would measure field resistance and contact Basler. They might even be able to cross reference your existing regulator. Look at this:

http://www.basler.com/VRSelector/VRSelector/

 

[takoateli]

Guys,

Thanks so much! Yes, the gen is 13KW, I don't know why my fingers typed 13KV in the title of the post!

Since I have an identical generator here that's working, shouldn't I just measure the field voltage and current with the generator under load and no load to know what I need?

Of course I'll also measure field resistance with the machine stopped.

Thanks!
Greg

 

[IBRCAN]

Yes, measure field parameters on the generator that is working.

 

[takoateli]

Thanks everyone who posted. Here's what I measured:

Field resistance: 27ohms
Field excitation voltage (no load on generator) 8VDC
Field excitation voltage (moderate load on generator) 10VDC
Field excitation current (no load on generator) 170mA
Field excitation current (moderate load on generator) 370mA
Sense input voltage to the AVR 218VAC (comes off two windings)

Also the original AVR says DST-51 on it.

I also checked the Field excitation voltage with my meter in AC, and it read 20VAC, but I'm assuming this bit of information is not of any value, I'm assuming it's an AC component that's generated by the AVR's DC switching circuit that feeds the field winding.

Greg

 

[wayne440]

I have had good results here. Call them with the info in your last post and a solution should be forthcoming.

http://www.flightsystems.com/

 

[takoateli]

Thanks!

Greg

 

[redlinej]

things you need to know when selecting a avr:
1.the resistance of the exciter coil.
2.the generator terminal voltage L-N or L-L.
3.if the generator is brushless or brush.
4. if the present avr is using terminal voltage for sensing or a separate votlage fo the stator coil.
N.B there is a company in the usa that have replacement ave for all types of generator www.mtspowerproducts.com

 

[takoateli]

1.the resistance of the exciter coil.

27ohms

2.the generator terminal voltage L-N or L-L.

L - L

3.if the generator is brushless or brush.

Brushless

4. if the present avr is using terminal voltage for sensing or a separate votlage fo the stator coil.

The schematic shows the present sensing is off taps on the main stator windings. This is a six wire alternator wired in star. Two of the main stator windings have taps that go to the AVR sense.

I'm going to contact the place you mentioned.

Thanks!