SIP Charnwood Saw Amperage confusion

[Robin Wood]

Hi everyone! This is my first post here

I'm currently searching for a table saw that can be ran off domestic 13A power.

I'm a little confused.

The Charnwood W650 has a 3HP 2200W motor. Charnwood state it can be ran on a standard domestic 13A socket.
The SIP 10" has a 3HP 2200W motor. SIP state this is a 16A motor and therefore comes with a 16A plug.

Normally, a standard 13A socket should be able to take a load of up to around 2800W, so I'm unsure of SIP's 16A rating on basically the same electrical spec as the Charnwood?

Can anybody shed any light on this?

Thank you!

 

[CHJ]

Motors invariably take two or three times their working current on start up surge.
A lot depends upon the inertia required to get things moving.

One may have a soft start feature or lower mechanical load to overcome on start up.

The characteristics of your electrical supply and protection devices also have a bearing on how they will perform.

 

[Robin Wood]

I'm aware that a motor upon start up can surge the supply for a second or two, but this does not answer why two table saws with the same spec motor are rated differently. Bearing in mind they both run at 2200w, this would not make any difference as to how they run.

There is a 600w headroom on these saws, which is why I'm wondering why one is rated at 16A and the other at 13A....

It doesn't make sense.

This also applies to Axminster and Jet saws of the same specification as the previously mentioned saws.

I'll email all companies tomorrow and find out why these saws are rated at 16A.

Thanks for your input!

 

[sunnybob]

its all about motor efficiency, as was said. An old design motor is more brutal on start up, and could cause nuisance tripping on modern supplies with up to date rcds and mcbs, making for lots of warranty calls and bad reputations, so the maker rates it as a higher spec.
A modern soft start motor can easily run on a 13 amp plug.

 

[MikeJhn]

If you find your MCB is tripping out with motor or transformer surge, change the MCB to a "D" type these are designed to take a motor surge and not trip.

Sorry that's C type in the UK: https://www.tlc-direct.co.uk/Products/HGNC132.html

A UK ring main should be protected by a 32amp MCB as long as there is nothing else on that ring main drawing power it should not trip out with a 2200Watt load.

Mike

 

[CHJ]

I'm aware that a motor upon start up can surge the supply for a second or two, but this does not answer why two table saws with the same spec motor are rated differently. Bearing in mind they both run at 2200w, this would not make any difference as to how they run.

..

You are making assumptions and missing the point.

As others have said the manufactures are expecting you to have problems starting the machines on modern electrical installations unless provided with a supply rated for the start up surge.
It's not a statement about Running Power needed.

The actual running current under load may well be very similar.

On an old property with a 30 amp fuse wire protected ring main they will both start no problem, on a modern domestic rated system with a fast acting MCD they will most likely trip it, even the 13 amp units may do this on some systems.

Length and gauge of feed wires or extensions and the associated initial surge volts drop against the spin up time of the motor all come into play, the 16 amp rated units are considered by the supplier to need a 16 amp rated feed to operate reliably in normal circumstances on modern supply systems.