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Heater Pack

Workshopshed

Here's a close up picture of the "Heater Pack" mentioned in my status message.  

  "Yes, they are motor thermal overload elements, known as 'heaters' in old school speak. The elements would screw into a holder that would house the auxiliary contact and operating mechanism. So you could select the best size heater element to match the motor and install them into the holder.

 

Instead of holding multiple thermal overloads as we do now, we would just have the holder and then a range of different heater elements to select from.

 

Some work on bending a metal strip to operate the contacts, similar to modern thermal overload elements and some are melting alloy types that have a star wheel held solid in a solder pot and the heat through the element would melt the soda and allow the star wheel to rotate and flip the mechanism to break the contacts. The ones you have look more like the former.

 

I will have a look at work tomorrow and see if I have a complete assembly and take some pictures if so.

 

Great idea for the maker box though!"

image

  • Had a look at work today, but no spares in the stores image, but I did manage to retrieve the instruction sheet for the type we use. I am also aware of some old units installed in a redundant panel that I will try and get to next week.

     

    They are old Allen West Type R overloads and are now manufactured by Whippendell Marine

     

    From their website you can see how they are put together;

     

    imageimage

    They come in two flavours, the first on the left have the motor current fed directly through the heater elements. This range have heaters covering 0.21-0.25A up to 60-72A. The second style on the above right are mounted on top of a current transformer and extend the range of the overloads from 61-73A up to 692-832A.

     

    image

     

    The standard type has only one housing that will take the whole range of elements. Up to 27A, they use the standard screw connections. Above 27A, they offer extended screw clamps as seen on the first overload in the picture on the left.

     

    Thus, a couple of spare housings and a range of the elements you require and you can cover all of the spares you need, in comparison to the more modern style thermal overloads, where a complete overload is required for each current range needed. Seen below for the Siemens range of overloads.

     

    image

    The downside to these older style overloads is that they have to be screw mounted in the panel on their own and wired to the contractor. Unlike the modern ones that are configured to directly mount on the contactor and connect into the terminals. This means of course, that you have to use physically compatible contactors and overloads, where as with the old style, you could use any electrically compatible contactor.

     

    mm, I may have the manual as a scanned pdf, but do not appear to be able to attach it.

     

    Kind regards

  • in reply to three-phase

    To attach the PDF, use the advanced editor. (click on the link in the upper right)

     

    Jack

  • in reply to jack.chaney56

    Thanks pdf successfully uploaded

    Attachments:
    imageAllen West Type R Overloads.pdf