Placement of Current sensor toriods

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maniago
Posts: 45
Joined: Mon Mar 12, 2018 10:34 pm

Placement of Current sensor toriods

Post by maniago »

I understand the basic concept of the toriod and the magnetic field generated by the current running thru the wire. I have them mounted in free space on their respective alternator wires as in the pic, but I'd actually like to snug them up to the engine mount instead, to make the situation more solid and take the strain off the wires. Given the mount is steel, will this throw off the magnetic field enough as to be undesirable? Or should I leave them mounted the way I have it?

BTW the wire ties are just temporary. Everything get laced at the end.

Thanks for any advice.
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GRT_Jeff
Posts: 660
Joined: Tue Dec 11, 2012 12:11 am

Re: Placement of Current sensor toriods

Post by GRT_Jeff »

The steel by itself shouldn't have an impact. I think an outside magnetic field must cancel out in the sensing element. None of the documents I found comment on mounting location or proximity to other fields. The high temperature and heating and cooling cycles near the engine may be a problem. The sensor is rated to 125 C (257 F).
maniago
Posts: 45
Joined: Mon Mar 12, 2018 10:34 pm

Re: Placement of Current sensor toriods

Post by maniago »

Ok great, thanks Jeff. I hadnt considered that a bunch of wires around a ferrite core would have a temp limit. That must be the green plasty dip covering on the toriod.....one would have thought theyd use enamel like the magnetic wire inside......but I'll take a look at moving it inside; aluminum to mount it to and I can probably get it close enough to the EIS to direct connect the wires to the d-sub vs wire splice.

Thanks again.
Bobturner
Posts: 429
Joined: Mon Mar 11, 2013 6:34 pm

Re: Placement of Current sensor toriods

Post by Bobturner »

maniago wrote:Ok great, thanks Jeff. I hadnt considered that a bunch of wires around a ferrite core would have a temp limit. That must be the green plasty dip covering on the toriod.....one would have thought theyd use enamel like the magnetic wire inside......but I'll take a look at moving it inside; aluminum to mount it to and I can probably get it close enough to the EIS to direct connect the wires to the d-sub vs wire splice.

Thanks again.
It’s a bit more than a bunch of wires. Inside is a ‘Hall effect’ sensor. It’s a solid state device, and thus doesn’t like high temperatures.
maniago
Posts: 45
Joined: Mon Mar 12, 2018 10:34 pm

Re: Placement of Current sensor toriods

Post by maniago »

I moved it, but its a bad move. All my batteries, alternators and A,B and crossfeed buss solenoids that are on the firewall are drawing (when all are on) up to 4.5 amps that are then unaccounted for. This will only work if you have a heavy old school lead-acid batt that you had to put in the back cabin for weight and balance. Noone does that anymore with LIPO4 and similar small weight high power batts such as are available now.

Jeff - you guys need to rethink the temp tolerance of this toriod.....I cant be the only one building with Nuckholls Z14 etc that puts the toroid(s) logically in the engine compartment.
GRT_Jeff
Posts: 660
Joined: Tue Dec 11, 2012 12:11 am

Re: Placement of Current sensor toriods

Post by GRT_Jeff »

I didn't say you had to keep it in the cabin. Our current sensor installation document says you can install on either side of the firewall. 125 degrees Celsius / 257 degrees Fahrenheit is a high tolerance.
maniago
Posts: 45
Joined: Mon Mar 12, 2018 10:34 pm

Re: Placement of Current sensor toriods

Post by maniago »

Ack, ok my bad. I read 125F. 125C, yeah thats no problem. Back to the engine mount they go.

Sorry bout that.
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