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Identifying retarder voltage

(@gasssed)
Member

So after spending the last 12 months working on a plan and previously asking as many questions as I can, I've had someone suggest that the retarder in the sun roadamatic I'm converting may be a 24v unit. 

 

Is anyone able to give me a simple method of ID? 

Googling model numbers does not provide any answers. 

Quote
Topic starter Posted : 23/01/2021 6:53 am
(@radics1)
Member

Try measuring the total resistance of the coils. If it is a 24V system,you will measure low resistance. Acc. to Frenelsa spec, a 192V brake has 10.1R resitance,resulting max current of 19A. I think 24V version should have around 1.2-1.3R.

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Posted : 23/01/2021 6:44 pm
(@gasssed)
Member

@radics1

 

This is good news! Total resistance measures around 15ohms

 

So would assume that it's not a 24v unit and therefore I don't need to rewire the coils. 

 

Great news!

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Topic starter Posted : 25/01/2021 4:36 am
(@radics1)
Member

Well,you need to be careful. This info was valid for one type of retarder.However with 15R it is either 96v or 192 in my opinion.

 

Here is a spec for a Telma brake. I dont know wich brand you have,but the wiring looks similar:

https://www.telmausa.com/Downloads/OC442107a.pdf

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Posted : 25/01/2021 6:56 am
(@gasssed)
Member

@radics1

Mine is a CA135 unit. 

From what I've seen it's not possible to assess the coil wiring visually without removing the hub assembly and an end plate- something I would rather avoid. 

 

I had the unit powered and controlled with the yourdyno system (including power supply) @192 volts. 

 

The coils emit an audible hum once load is added. 

 

I ramped to 50% and then progressively to 100% in the software and verified brake application through spinning the roller 

 

I'm hoping to get a car on later in the week. (just finalising tie down points at the rear) 

 

I'd expect that if the unit was wired for 24v or otherwise, it would draw massive current and pop the internal fuse of the yourdyno power supply? 

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Topic starter Posted : 01/02/2021 9:59 am
(@radics1)
Member

Yes,i think if this would be a 24V retarder,high current would flow though.

Noise is normal,i really dont like the sound of it,so i dont apply load until the rollers are not moving.

 

 

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Posted : 01/02/2021 10:55 am
(@admin)
Member Admin

16 coils and 15 ohm then that's a 192V unit

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Posted : 05/02/2021 11:54 pm
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