cable size for lister starter motor

[vintagescubaman]

well im on the final leg of my engine room re wire and im pleased to say its all going well, and dare i say, working! Im now about to renew the starter cables, it would appear that the existing cables are 35 mm square, what would people recommend as a suitable cable size for a lister ha2 starter notor? I have some spare 50 mm that i thought might do the job?

[paulcatchpole]

A cursory calculation suggests the following as an example:

 

200A, 4m total length (2m there and back), .5v permissable drop, says =18/((C17*1000/D17)/E17) (on my spreadsheet! ) : 28.8mmsq required.

 

Our ST2 (and SR3) uses a 2.2kw starter, drawing c. 200A, so the above is worked on that.

 

We've a 3m total return run, and are using 25mmsq cable for it, no problem here.

 

I suspect your 50mmsq will be sufficient!

 

PC

[FORTUNATA]

Starter engine wires don't normally need to be large as they only have to take heavy current for small time periods.

 

well im on the final leg of my engine room re wire and im pleased to say its all going well, and dare i say, working! Im now about to renew the starter cables, it would appear that the existing cables are 35 mm square, what would people recommend as a suitable cable size for a lister ha2 starter notor? I have some spare 50 mm that i thought might do the job?

[paulcatchpole]

Starter engine wires don't normally need to be large as they only have to take heavy current for small time periods.

 

I think they're one of the BSS-specified cables which have to be at least 25mmsq.

 

Edit, in fact I'm wrong, they're not on the following list.

 

 

Even so, I can't see a good reason to use less than 25mmsq, when you'd be buying a fair bit to cable all of the above anyway.

 

I'd quite like my cable to be continuously rated for whatever it's drawing - do you want it to become a heating element, when your starter jams up?

 

PC