Cable temperature

[bigstrong]

Hi,

I've had a few occasions where a 3 pin plug or the switch socket outlet get burnt. This usually happen to chiller unit.
The cable was properly size up according to the drawn current and also well above 13 Ampere when those single phase 3 pin plug are used.

The trouble usually happens when the chiller compressor runs out of refrigerant. In normal situation, the compressor will on and off according to the set water temperature. In the event where compressor run non stop because the water temperature does not reach the set temperature, the heat starts to build up. Usually the pin of the plug will get hot and followed by the switch socket out and then the plug.

My question is, how much continuous current and how long a time it will take before all the heating up takes place, assuming ampere is below 13 Amps and it doesn't blow the fuse.
Are there any standard tables that we can refer to.

Thank you all.

 

[plugsandsparks]

Not really, the heating depends on the quality of the plug / socket combination and quality of terminations in both plug and socket. Sometimes it just better to put it on a 16A commando, on a 16 breaker, if you can.
cheers
P&S

 

[James]

what type of plug and socket are you using?

 

[pc1966]

A 13A plug & socket is fine when new and clean contacts, etc, but years later when tarnished and inserted just once (so high resistance contact, etc) you may well find it struggles with 13A. For any high power load I would try inseting and withdrawing seveal times, and operating the on/off switch several times (no plug installed) to clean any contacts before use.

However, if you see it one a regular basis either the choice of hardware is poor quality, or the equipment is going over 13A for long periods (but not quite enough to blow the fuse).

As above, check the specification carefully, and if it matters then a 16A command socket on a dedicated radial circuit is going to solve that problem for you.

 

[Pete999]

Hi,

I've had a few occasions where a 3 pin plug or the switch socket outlet get burnt. This usually happen to chiller unit.
The cable was properly size up according to the drawn current and also well above 13 Ampere when those single phase 3 pin plug are used.

The trouble usually happens when the chiller compressor runs out of refrigerant. In normal situation, the compressor will on and off according to the set water temperature. In the event where compressor run non stop because the water temperature does not reach the set temperature, the heat starts to build up. Usually the pin of the plug will get hot and followed by the switch socket out and then the plug.

My question is, how much continuous current and how long a time it will take before all the heating up takes place, assuming ampere is below 13 Amps and it doesn't blow the fuse.
Are there any standard tables that we can refer to.

Thank you all.

The Chiller shouldn't "Run out of Refrigerant it's a sealed unit" unit ought to be on a dedicated circuit protected by a suitable OCPD and hard wired, you need to get the leak in the Chiller system sorted ASAP

 

[bigstrong]

Not really, the heating depends on the quality of the plug / socket combination and quality of terminations in both plug and socket. Sometimes it just better to put it on a 16A commando, on a 16 breaker, if you can.
cheers
P&S

Thanks you for your input.

Yes, agree about putting those equipment on 16A or isolator and also the quality of plug, terminations etc plays a part that leads to unfortunate incidence. My concern is, let's say a given current of 10A at 230Vac, using a 2.5mm sq 3 core pvc cable with copper conductor. What would be the temperature rise of conductor and pin of 3 pin plug versus time.

 

[bigstrong]

what type of plug and socket are you using?

Type G, 13A 220 - 240V

 

[bigstrong]

A 13A plug & socket is fine when new and clean contacts, etc, but years later when tarnished and inserted just once (so high resistance contact, etc) you may well find it struggles with 13A. For any high power load I would try inseting and withdrawing seveal times, and operating the on/off switch several times (no plug installed) to clean any contacts before use.

However, if you see it one a regular basis either the choice of hardware is poor quality, or the equipment is going over 13A for long periods (but not quite enough to blow the fuse).

As above, check the specification carefully, and if it matters then a 16A command socket on a dedicated radial circuit is going to solve that problem for you.

Yes, I tend to agree.
Poor contact between the pin and socket outlet. I've had some older installation happening that way. Few days a go, I have a 3 month old installation giving that same problem. I would have to say it's the manufacturer defect.
Then again, its rather difficult to see if the metal prong inside the socket outlet that mate with the pin of plug are in good condition.

 

[bigstrong]

The Chiller shouldn't "Run out of Refrigerant it's a sealed unit" unit ought to be on a dedicated circuit protected by a suitable OCPD and hard wired, you need to get the leak in the Chiller system sorted ASAP

Thank you for your input.
Yes, we got it tested today and the gas seems okay. There wasn't any refrigerant leak. The cause of burnt plug and socket outlet could be due to poor electrical contact.