Reduce cable

[Jako13!]

Hi guys what do you think of this. There’s been a temporary bit of plant wired up out of an existing circuit which is an 100amp supply I believe. The circuit then goes through a soft start to a local isolator about 50meters away. The motor is supplied with 10mm flex but due to the flex not being long enough someone has used a JB and extended to the isolator with 6mm flex. My thoughts are the 6mm is a bit close as the motors FLC is 41 Amp. I’m also aware the main fuses are 100amp so again oversized. Another question was the overload was set to 41 amps I know this isn’t ideal to rely on but would the cable be protected?


thanks guys

 

[westward10]

The thermal relay will limit the current flow what it won't do is offer short circuit protection. Is it single or three phase.

 

[Jako13!]

Hi guys what do you think of this. There’s been a temporary bit of plant wired up out of an existing circuit which is an 100amp supply I believe. The circuit then goes through a soft start to a local isolator about 50meters away. The motor is supplied with 10mm flex but due to the flex not being long enough someone has used a JB and extended to the isolator with 6mm flex. My thoughts are the 6mm is a bit close as the motors FLC is 41 Amp. I’m also aware the main fuses are 100amp so again oversized. Another question was the overload was set to 41 amps I know this isn’t ideal to rely on but would the cable be protected?


thanks guy

The thermal relay will limit the current flow what it won't do is offer short circuit protection. Is it single or three phase.

Sorry it’s 3 phase

 

[westward10]

What type of cable is the 6.0.

 

[Jako13!]

What type of cable is the 6.0.

It’s 4 core flex, but the actual manufacturer is Lapp it’s 130h ?

 

[westward10]

That is a YY cable and a four core 6.0 will carry 44A.

 

[Jako13!]

That is a YY cable and a four core 6.0 will carry 44A

Thanks westward10 so ideally we’d want to install 40 amp fuses to protect the cable? Also just curious why won’t an overload pic up a short as I thought the overload will pick up the overcurrent and trip or is it more todo with the delay on the overload?
Thanks