Diversity Calc Commercial Dishwasher 6.5kW single element

[DefyG]

It's most likely been converted from 6.5kw heater to 2.1kw heater by the supplier, either from new or as used.

So not a fixed 6.5kW load as per original OP, but one that can be terminated probably for 1ph 2.1kW element, which would account for it being ok (Not tripping or any thermal damage) on a 13A plug/socket.
And at 6.5kW could be 3ph??

 

[Ray Pooley]

Built and delivered from warehouse as stock 25/09/2017. 4.0mm² 3 core black flex.
Three years old. New to the customer. That's the way it is. I don't have a picture of the plug ans socket. I'll take one tomorrow. The problem it has is a faulty main boiler thermostat. This is the first issue it has had since new.
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An interesting experiment by John Ward. The destruction of a power cable. The point to note in this video is that the plug is a 13A plug and fuse. These continue to serve current up to 23.4 VAC.
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And here's teh video.

View: https://www.youtube.com/watch?v=rfU5lzXAHAQ&t=61s&ab_channel=JohnWard

 

[DefyG]

Why would anyone put it on a 13A plug when the nameplate clearly states 30A?
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Not sure what your point is with the video ............ Its still doesn't qualify for diversity and is currently incorrectly terminated .... 'in my book'!

 

[snowhead]

I'm not sure why this thread has run to 23 posts.
As above a 13amp plug and socket is not suitable for a 6.5kw load, if that's what it really is.
Diversity doesn't come in to it.
It needs a suitable plug / socket or connection and a suitable supply to it, if the existing one is not.

 

[davesparks]

The data plate clearly states that it has a power consumption of 6.5kW and requires a 30A supply so that is what it should be connected to. If they want it on a plug then a 32A plug would be appropriate.

Diversity cannot be applied to the supply to the appliance if it is a single heating element as that element will only be either on or off, appliances with multiple heating elements controlled by different thermostats can have diversity applied as they will all be cycling on and off at different times.

Diversity can be applied when considering the supply to the DB that then feeds this machine (assuming it is fed from a DB which feeds multiple circuits) but this does not have any bearing on the supply to the machine itself.

As to how the plug has not burned out yet, it is probably probably luck or an incorrect fuse or a modified appliance......

 

[pc1966]

At 30A a genuine 13A fuse would below somewhere between 1s and 40s, so it seems very unlikely it really is that sort of a load.

 

[DPG]

You say it has 4mm flex fitted. Can you show a picture of the 13A plug to show how it has been fitted.

 

[Jim_e_Jib]

In the link that Westward provided in #19, it says:

Machine will be set for 30amp supply with relevent cable, if they are ordered for 2.6kw 13 amp supply, the cable will need to be changed by the installation engineer as a UK 3 pin plug will not fit onto the cable

Has it been supplied as the 2.6KW unit and the installation engineer just butchered a 13amp plug on the supplied cable rather than replacing it?

 

[Vortigern]

Hope it's got a PAT test cert.

 

[DPG]

In the link that Westward provided in #19, it says:

Machine will be set for 30amp supply with relevent cable, if they are ordered for 2.6kw 13 amp supply, the cable will need to be changed by the installation engineer as a UK 3 pin plug will not fit onto the cable

Has it been supplied as the 2.6KW unit and the installation engineer just butchered a 13amp plug on the supplied cable rather than replacing it?

Yes, It sounds like they're put a 13A plug on 4mm flex to me!

 

[Ray Pooley]

For the record. Plug and socket undamaged. No signs of overheating on plug or socket. Been lke this for 3 years. Machine was brought in to replace a 3.1kW machine. Installed by the vendor.

 

[DPG]

So, can you post a photo of how the plug is wired. And how the cord grip is fitted. Have you looked yet? I think we all know how it's going to look.

 

[telectrix]

It's easy to fit a plug on a 4mm flex. first curt back the sheath so the cord grip can clamp om the pretty coloured conductor basic insulation. then cut half the strands off the stripped ends. Don't forget to fit 1.5mm ferrules before inserting into the pins. Tighten with a calibrated torque screwdriver. And remember to fit the "plug top" before inserting into the socket outlet, wich, of course will be the 3rd double along a 4 socket unfused spur.

 

[Ray Pooley]

It's easy to fit a plug on a 4mm flex. first curt back the sheath so the cord grip can clamp om the pretty coloured conductor basic insulation. then cut half the strands off the stripped ends. Don't forget to fit 1.5mm ferrules before inserting into the pins. Tighten with a calibrated torque screwdriver. And remember to fit the "plug top" before inserting into the socket outlet, wich, of course will be the 3rd double along a 4 socket unfused spur.

Exactly right except the strands don't appear to have been trimmed. No ferrules in this case.

 

[DPG]

Exactly right except the strands don't appear to have been trimmed. No ferrules in this case.

So it's connected up in a non suitable way which should be sorted ideally.

 

[snowhead]

Did you check the current to see if it really is 6.5kw?

 

[Ray Pooley]

So it's connected up in a non suitable way which should be sorted ideally.

Not recommened that's true. But here's what I know. There are no signs of damage to either plug or socket after 3 years of service 7 days a week. About 3,300 wash cycles. The plug has a 13A fuse in it that is in tact and has never needed to replaced. That's not to say that the current doesn't rise above 13A. I posted a John ward video earlier that show John destroying a power cable. The socket, plug and fuse that John uses in his experiment are all 13A and don't appear to suffer even though the current gets as high as 23A over a period of about 30 minutes. Theoretically the fuse should have blown at 21A.

Did you check the current to see if it really is 6.5kw?

No. It's not what I am there to do. I don't think I need to tbh. It's going to me more than 13A. This is purely an observation. I will make a recommendation but I doubt it will be followed up. There are no signs of damage to either plug or socket after 3 years of service 7 days a week. About 3,300 wash cycles. The plug has a 13A fuse in it that is in tact and has never needed to replaced. That's not to say that the current doesn't rise above 13A. I posted a John ward video earlier that show John destroying a power cable. The socket, plug and fuse that John uses in his experiment are all 13A and don't appear to suffer even though the current gets as high as 23A over a period of about 30 minutes. Theoretically the fuse should have blown at 21A. Finally, the circuit is supported by a B32 so the only weak link, so to speak, is the actual plug and socket. From the owner's perpective there doesn't appear to be any real incentive to go to the expense of installing a dedicated circuit.

 

[DPG]

Not recommened that's true. But here's what I know. There are no signs of damage to either plug or socket after 3 years of service 7 days a week. About 3,300 wash cycles. The plug has a 13A fuse in it that is in tact and has never needed to replaced. That's not to say that the current doesn't rise above 13A. I posted a John ward video earlier that show John destroying a power cable. The socket, plug and fuse that John uses in his experiment are all 13A and don't appear to suffer even though the current gets as high as 23A over a period of about 30 minutes. Theoretically the fuse should have blown at 21A.

No. It's not what I am there to do. I don't think I need to tbh. It's going to me more than 13A. This is purely an observation. I will make a recommendation but I doubt it will be followed up. There are no signs of damage to either plug or socket after 3 years of service 7 days a week. About 3,300 wash cycles. The plug has a 13A fuse in it that is in tact and has never needed to replaced. That's not to say that the current doesn't rise above 13A. I posted a John ward video earlier that show John destroying a power cable. The socket, plug and fuse that John uses in his experiment are all 13A and don't appear to suffer even though the current gets as high as 23A over a period of about 30 minutes. Theoretically the fuse should have blown at 21A. Finally, the circuit is supported by a B32 so the only weak link, so to speak, is the actual plug and socket. From the owner's perpective there doesn't appear to be any real incentive to go to the expense of installing a dedicated circuit.

I would strongly recommend that they look at it. Will only get worse over time not better.

And get a suitable method of connection that is compatible with 4mm cable.

 

[westward10]

Not recommened that's true. But here's what I know. There are no signs of damage to either plug or socket after 3 years of service 7 days a week. About 3,300 wash cycles. The plug has a 13A fuse in it that is in tact and has never needed to replaced. That's not to say that the current doesn't rise above 13A. I posted a John ward video earlier that show John destroying a power cable. The socket, plug and fuse that John uses in his experiment are all 13A and don't appear to suffer even though the current gets as high as 23A over a period of about 30 minutes. Theoretically the fuse should have blown at 21A.

No. It's not what I am there to do. I don't think I need to tbh. It's going to me more than 13A. This is purely an observation. I will make a recommendation but I doubt it will be followed up. There are no signs of damage to either plug or socket after 3 years of service 7 days a week. About 3,300 wash cycles. The plug has a 13A fuse in it that is in tact and has never needed to replaced. That's not to say that the current doesn't rise above 13A. I posted a John ward video earlier that show John destroying a power cable. The socket, plug and fuse that John uses in his experiment are all 13A and don't appear to suffer even though the current gets as high as 23A over a period of about 30 minutes. Theoretically the fuse should have blown at 21A. Finally, the circuit is supported by a B32 so the only weak link, so to speak, is the actual plug and socket. From the owner's perpective there doesn't appear to be any real incentive to go to the expense of installing a dedicated circuit.

It's no good speculating and watching YouTube videos. In my guessed opinion from the link I posted in #19 is that the load is nowhere near what you are predicting and that it has been altered to enable 13A operation but the flex has not been reduced in csa. Or it is exceeding the13A rating but nowhere near what you think. If you are going to suggest someone takes action with this be precise with your information and measure the current draw.

 

[Ray Pooley]

It's no good speculating and watching YouTube videos. In my guessed opinion from the link I posted in #19 is that the load is nowhere near what you are predicting and that it has been altered to enable 13A operation but the flex has not been reduced in csa. Or it is exceeding the13A rating but nowhere near what you think. If you are going to suggest someone takes action with this be precise with your information and measure the current draw.

It hasn't been altered.