Grounding shielding around motor cable

AC, DC, amps, volts and kilowatt. It's all discussed in here
Post Reply
soyachips
Groupie
Posts: 177
Joined: Mon, 04 Aug 2008, 05:44
Real Name: Andrew Lo
Location: Sydney

Grounding shielding around motor cable

Post by soyachips » Wed, 30 Oct 2019, 03:56

The cables that comes out of my hub motor have shielding around them and someone recently said I should ground the shielding to the bike frame. Is this correct and are there any tricks to doing this?

User avatar
jonescg
Senior Member
Posts: 3050
Joined: Thu, 21 Jan 2010, 23:05
Real Name: Chris Jones
Location: Perth, WA.

Re: Grounding shielding around motor cable

Post by jonescg » Wed, 30 Oct 2019, 09:34

Check for continuity between the shield and the motor chassis. If there is none, that's good - it means you can connect the shielding cable to the same shield as your BMS communications. You want to minimise any potential ground loops, so have all shields meet at the same point if possible.
AEVA National Secretary, WA branch chair.

User avatar
Richo
Senior Member
Posts: 3737
Joined: Mon, 16 Jun 2008, 00:19
Real Name: Richard
Location: Perth, WA

Re: Grounding shielding around motor cable

Post by Richo » Wed, 30 Oct 2019, 12:54

Power wires or signal wires?

Metal gland.
Usually this is done at the source (motor controller).
You really should check that they have no continuity to any of the wires.
Otherwise you could earth your ground...
So the short answer is NO but the long answer is YES.
Help prevent road rage - get outta my way!

User avatar
bladecar
Senior Member
Posts: 446
Joined: Tue, 05 Jul 2011, 16:32
Location: Brisbane

Re: Grounding shielding around motor cable

Post by bladecar » Wed, 06 Nov 2019, 05:12

I wonder if there should be a separate listing on this site for "technical assistance" in order to separate those dedicated to technical matters from those dedicated to Australian Electric Vehicles.

User avatar
jonescg
Senior Member
Posts: 3050
Joined: Thu, 21 Jan 2010, 23:05
Real Name: Chris Jones
Location: Perth, WA.

Re: Grounding shielding around motor cable

Post by jonescg » Wed, 06 Nov 2019, 06:48

I think it resides in the correct forum 😕
AEVA National Secretary, WA branch chair.

User avatar
Richo
Senior Member
Posts: 3737
Joined: Mon, 16 Jun 2008, 00:19
Real Name: Richard
Location: Perth, WA

Re: Grounding shielding around motor cable

Post by Richo » Wed, 06 Nov 2019, 12:46

Mmmm the "help me I'm stuck" page :lol:

Only people with pace makers worry about EMC :lol: :o
So the short answer is NO but the long answer is YES.
Help prevent road rage - get outta my way!

Rusdy
Groupie
Posts: 216
Joined: Mon, 09 Jun 2014, 16:45
Real Name: Rusdy
Location: Australia
Contact:

Re: Grounding shielding around motor cable

Post by Rusdy » Wed, 11 Dec 2019, 13:15

I'm still confused with 'ground loops'. I thought 'ground loops' only happens when there is a poor ground connection (or long distance wiring). So, when current induces on the cable shield, it will in turn induce current to signal wire.

So, if you have good ground (such as car or bike's frame), then, in theory, you can 'ground' the shield to your heart's content, right?

The more I read about this, the more confused I am, example, this link.

User avatar
brunohill
Groupie
Posts: 97
Joined: Thu, 08 Feb 2018, 22:32
Real Name: Phil
Location: Wangaratta

Re: Grounding shielding around motor cable

Post by brunohill » Wed, 11 Dec 2019, 18:09

I think Rudsy at lower frequencies this is still the case, but these days we are using higher frequency AC, digitally clipping it producing harmonics and actually producing RF radiation as distinct from just induction problems.

Post Reply