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Dorman, ECC genset

constman

Registered
I recently purchaced at auction a genset with a Dorman engine and an Ecc generator it is rated at 400V, 376A and 208 Kw. It was used as a reserve power supply in the Copenhagen hospital. The motor starts and runs very well, I am however having problems with the generator. I believe the problem is entirely in the AVR and I'm hoping to get some answers here. At first it would only produce 200V, then I read online, if there was an external potentiometer or CT then those respective terminals need to be jumped. This machine did in fact have an external CT and I have jumped the terminals marked P1, P2 and P3 in various ways. The voltage has jumped up to 360V but the frequency is behaving very strangly. At idle The frequency between L1 and L2 is around 200 Hz, between L2 and L3 120 Hz and L1and L3 560Hz. The frequency fluctuates greatly. I live in Sweden so 50 Hz is desireable. Can anybody tell me what's going on?
 

LV50_Aaron

Registered
I recently purchaced at auction a genset with a Dorman engine and an Ecc generator it is rated at 400V, 376A and 208 Kw. It was used as a reserve power supply in the Copenhagen hospital. The motor starts and runs very well, I am however having problems with the generator. I believe the problem is entirely in the AVR and I'm hoping to get some answers here. At first it would only produce 200V, then I read online, if there was an external potentiometer or CT then those respective terminals need to be jumped. This machine did in fact have an external CT and I have jumped the terminals marked P1, P2 and P3 in various ways. The voltage has jumped up to 360V but the frequency is behaving very strangly. At idle The frequency between L1 and L2 is around 200 Hz, between L2 and L3 120 Hz and L1and L3 560Hz. The frequency fluctuates greatly. I live in Sweden so 50 Hz is desireable. Can anybody tell me what's going on?
What type of AVR does the generator have installed? Do you know if this machine was originally in parallel with other gensets in the hospital?
What are you measuring the frequency and voltages with? Something seems wrong with these readings. Frequency is relative to speed so what you are describing in measurements should also be evident in wildly unstable engine speed.
 
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constman

Registered
What type of AVR does the generator have installed? Do you know if this machine was originally in parallel with other gensets in the hospital?
What are you measuring the frequency and voltages with? Something seems wrong with these readings. Frequency is relative to speed so what you are describing in measurements should also be evident in wildly unstable engine speed.
 

constman

Registered
the avr is a type THR 150 MK III, manufactured by ECC. I'm measuring with a multimeter. At first I thought something must be wrong with it but when I measure in an outlet in my house I get 50 Hz. So I'm convinced it's not the multimeter. The engine is just idling, There is no way the frequency readings are from engine speed. I made it just a little slower and there was no electricity at all. I'm baffeled.
 

Radiomike

Registered
The output frequency is fixed to the engine speed, it is related to the number of poles on the generator. For a four pole machine 1500 rpm gives 50Hz. By ECC I assume this is the Electric Construction Company, I think these were taken over by Hawker Siddley. http://www.historywebsite.co.uk/Museum/Engineering/Electrical/TheECC.htm. Photographs of the set plus the AVR would be so helpful. If your multimeter is giving funny readings use a tachometer on the shaft. Does the generator have a name plate?

I would expect a potential voltage transformer to be present feeding the AVR plus an input for a compounding CT into the AVR.

Here is one ECC AVR instruction sheet https://www.google.ca/search?q=ECC+...AhWfFjQIHSMMAkAQBSgAegQIChAp&biw=1632&bih=867 this is for a brush-less set which I assume yours is. In the UK Roper Electronics specialise in AVR work repairs and spares, http://www.roperelectronics.co.uk/

So any more details would be helpful.

Mike
 

constman

Registered
Just want to thank everyone who reads and answers this. I should add, when this genset came into my possesion all wires were chopped off and all electronic devices external to the generator gone. So I don't know what equipment was with this machine when it was operating. The only clue I have is The terminals marked P1,P2 and P3 had wires attached that went external to the generator and were chopped off. Mike the instruction sheet you linked would be very helpful if I could just translate the markings on the sheet to the markings on my AVR. According to the sheet 1-3 , 2-4, and L-M should be linked. I don't have 4,L or M on my AVR. I thought 1 and 2 were for the potentiometer and P1,P2,P3 for the CT. If you look at my markings do you know which should be linked? I don't plan on having an external CT or potentiometer. I've linked pictures of the front and back of the AVR and the label of the generator.
 

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Radiomike

Registered
I had hoped the datasheet references would, as it is by the same manufacturer, have similar marking —alas no. The only thing is that X and XX appear to be the field connections. The older ANCIAC80 shows that there is a quadrature CT connection for parallel operation and a three phase transformer. Your AVR will also have these connections. So I think unless someone has a datasheet, you will either have to probe about inside the AVR for any more data or contact Roper Electronics who do service these. Roper may (for a fee) send you a connection sheet they will certainly be able to test it. A further option is to change the AVR for another.

Did you trace out where all the wires go, perhaps to a Voltage transformer and some current transformers?

Mike
 

constman

Registered
Hej again. I traced the wires. N is of course neutral, A leads to what appears to be a voltage transformer,B4 goes to one of the phases, X runs around the end of the stator and back to XX, P1,P2 and P3 go out of the box and are chopped off(I think to an external CT device). I tried to post a video of me measuring the voltage and frequency so you could see for yourself how it behaves, but this site doesn't allow videos. With no jumps V about 200 Frquency between 30 and 70Hz. With P1 and P3 jumped a stable 430V but frequency was different between the different phases and the highest about 950Hz. It requires an excess of 27000 RPM's to get 900Hz. I think my engine would explode around 5000 :) I sent a message to roper hoping they can explain what I need to do. Thanks for your help
 

Radiomike

Registered
To use an external CT for parallel operation it needs to be responsive to the quadrature component of current and voltage. It may be that P1, P2, and P3 went to a Star - Delta potential transformer as a means of deriving the correct phase relationship to the current transformer. This is clearly shown in the ANIAC80 data sheet wiring.

I wish you well with Roper, let us all know how it turns out.

Mike
 

Vanman

Subscriber
Last Subscription Date
06/10/2020
If you apply a small load such as a light bulb (or a few in series, depending upon the voltage), in parallel with your meter, you will most likely then be able to get reliable frequency readings. :brows:

Keith
 

constman

Registered
To use an external CT for parallel operation it needs to be responsive to the quadrature component of current and voltage. It may be that P1, P2, and P3 went to a Star - Delta potential transformer as a means of deriving the correct phase relationship to the current transformer. This is clearly shown in the ANIAC80 data sheet wiring.

I wish you well with Roper, let us all know how it turns out.

Mike
With carpentry as my vocation I can assure you that there is not much on that ANIAC80 data sheet that's clear to me. :) When I looked up quadrature it said the math process by which you make the area of a square equal to the area of a circle. I took that to mean x=√πr² but I don't see what it has to do with current or voltage :) :) I'm hoping roper will say Jump this terminal to that terminal and everything will be fine :) As you can see I'm in little over my head but I'm learning :) You seem knowledgable however and I'm grateful for that.
 

constman

Registered
If you apply a small load such as a light bulb (or a few in series, depending upon the voltage), in parallel with your meter, you will most likely then be able to get reliable frequency readings. :brows:

Keith
My engine doesn't have a belt driven fan with the radiator it has a 3 phase electric motor driven by the generator. I measured over that, the frequency didn't fluctuate as much but still very different over the different phases and still very high.
 

Radiomike

Registered
Quadrature is a term applied to the reactive component of current and power. This small brochure from Cummins outlines the idea. On the ANIAC80 sheet there is a small Delta - Star Transformer shown connected to 4 - 5 and 6 on the PC board and as T2 in figure 1.

Mike
 

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constman

Registered
Quadrature is a term applied to the reactive component of current and power. This small brochure from Cummins outlines the idea. On the ANIAC80 sheet there is a small Delta - Star Transformer shown connected to 4 - 5 and 6 on the PC board and as T2 in figure 1.

Mike
Thanks that was informative. I thought I would be able to adjust motor speed by getting electrical frequency to 50Hz. I believe now that I must get a tachometer and get my motor speed to 1500RPM's so I can adjust my AVR. I would like to see how my genset acts under load but if I could find a way to hook up all my electrical devices it still probably wouldn't come up to 10% of the total capacity. Is there any way to trick the machine?
 

Radiomike

Registered
A load bank will be a big project to do safely at 400 Volts. Your multi-meter is probably being confused by harmonics. However, before you start on the road to a load bank is the generated voltage stable on all three phases? You do not say if the connections are star (Y) or Delta Δ. If it is Y connected which would be the most common, how is the star point grounded? I don't know about the Swedish electrical code but it is usual for the star point to be grounded, this may have been done at the local switchboard in the hospital. The star point and the three phases form a four wire system with 240 Volt from phase to neutral. The generator set also needs to be securely grounded in some way.

The generator would have had some extensive protection, 378 amps can do a lot of damage. The short circuit current would be many times this. A good set of high rupture capacity fuses would be essential if you connect to a load bank, as well as an emergency stop system.

If you need a socket for the unit IEC 60309 covers types up to 800Amps and are common throughout Europe. https://en.wikipedia.org/wiki/IEC_60309

Mike
 

constman

Registered
A load bank will be a big project to do safely at 400 Volts. Your multi-meter is probably being confused by harmonics. However, before you start on the road to a load bank is the generated voltage stable on all three phases? You do not say if the connections are star (Y) or Delta Δ. If it is Y connected which would be the most common, how is the star point grounded? I don't know about the Swedish electrical code but it is usual for the star point to be grounded, this may have been done at the local switchboard in the hospital. The star point and the three phases form a four wire system with 240 Volt from phase to neutral. The generator set also needs to be securely grounded in some way.

The generator would have had some extensive protection, 378 amps can do a lot of damage. The short circuit current would be many times this. A good set of high rupture capacity fuses would be essential if you connect to a load bank, as well as an emergency stop system.

If you need a socket for the unit IEC 60309 covers types up to 800Amps and are common throughout Europe. https://en.wikipedia.org/wiki/IEC_60309

Mike
Thanks for all the information, as you've probably noticed I don't have much experience with this. I talked with a knowledgable man here in Gothenburg. He said the frequency readings I'm getting are not possable(he saw the video and there are no surges in the engine) and that my generator is making noise( harmonics) which my multimeter can't filter out. With the engine speed I'm usuing now I have a very stable 400V on all three phases. I'm not sure what star and delta connections are or how I can tell the difference, so I can't answer which I have. I have 400A fuses on all three phases but still I'm a little bit unsure about making my own load bank
 

Radiomike

Registered
I looked at the name plate again and see it says 400/230 so from this I can infer it is Y star connected. In the terminal box I expect to see four connections. Depending on the age they may be marked L1, L2 and L3 and N, possibly coloured Red / Yellow / Blue or may be U -V -W and N. Somewhere possibly in the terminal box will be a connection for the ground wire, often coloured green.

Are there any more current transformers within the generator, if you are going to load it then all current transformers must have their secondaries shorted to avoid damage.

The photo of the name plate is not clear as to the generator number and type, it may be possible to glean more information if we knew the generator type.

The 400Amp fuses may not have been the only protection when it was installed; I might have expected a large circuit breaker and some electronic protection for the generator. A 400Amp fuse could carry 1200Amps for 10 seconds before the fuse ruptures, this may vary according to the exact fuse type.

Mike
 

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