MCB rating for scissor lift ?

[PodOne]

Calling any electricians.

About to take delivery of a LGX35 3500kg lift with a 16amp plug.

It needs a 240v 16 amp C rated MCB. The motor/pump is rated at 2.2kw.

Do I need a 16amp 6KA or 10KA one?

Thanks

Andy

[RobH]

The kA rating is the maximum current that the MCB can safely break but remain serviceable.  The rating needed depends on the supply capability, as it reflects the peak currents (Prospective Fault Current) that can result from a direct short circuit either to earth or line-to-neutral.    6kA (6000Amps) should be sufficient for a typical domestic installation as the circuit impedance usually limits the peak attainable to a rather lower figure. 

 

[PodOne]

Thanks Rob your a star!

I've made the fatal mistake of consulting Dr Google and got more confused than normal  

I have a spare MCB slot in the consumer unit which by luck in the garage so was planning fitting as above the 16amp C curve MCB (6KA) into it and a short run of old style thick 2.5 red and black twin and earth to the 16A socket. 

Andy

[Charlie D]

10 hours ago, PodOne said:

...old style thick 2.5 red and black twin and earth...

Andy,

Back in the 1970s I was an electrician for a while. In those days all you needed to rewire a house was common sense and no one bothered if you had any sort of qualifications.

The problem you face today is that I don't think you are "Allowed" to wire into a consumer unit unless you have the relevant qualifications. As for using red and black wire you may well find yourself facing 10 years in Wormwood Scrubs for using such cable.

My personal view is that none of this really matters, but the problem comes if ever you have a fire or any sort of accident where an insurance company is involved.

They will do their best not to pay out by saying that the work was not done by a qualified electrician. (Who would probably have to provide you with some sort of certificate when the work was done.) and using the correct materials.

A few years ago we had subsidence and the man who was sent to inspect the damage tried his best to find a way not to pay out, even though we had done nothing wrong.

Charlie.

 

 

[BlueTR3A-5EKT]

39 minutes ago, Charlie D said:

Andy,

Back in the 1970s I was an electrician for a while. In those days all you needed to rewire a house was common sense and no one bothered if you had any sort of qualifications.

The problem you face today is that I don't think you are "Allowed" to wire into a consumer unit unless you have the relevant qualifications. As for using red and black wire you may well find yourself facing 10 years in Wormwood Scrubs for using such cable.

My personal view is that none of this really matters, but the problem comes if ever you have a fire or any sort of accident where an insurance company is involved.

They will do their best not to pay out by saying that the work was not done by a qualified electrician. (Who would probably have to provide you with some sort of certificate when the work was done.) and using the correct materials.

A few years ago we had subsidence and the man who was sent to inspect the damage tried his best to find a way not to pay out, even though we had done nothing wrong.

Charlie.

 

 

Open season?

https://scifi.stackexchange.com/questions/146511/death-penalty-for-insurance-company-directors#146514

 

[RobH]

2 minutes ago, BlueTR3A-5EKT said:

Open season?

Well in view of recent events in America, that does seem to be the case.  They have caught the (alleged) assassin though. 

[BlueTR3A-5EKT]

I have an electric shower unit and the installation was inspected and considered to have insufficient cable size for the distance and power consumption. The rectification by Souther Electric was to run an additional identical sized cable from the shower unit to the consumer unit.   That installation was certificated and a lot cheaper than the alternative of the existing cabling being replaced by a larger cross section conductor cable.   The electrician said it was an easier thing to work with too.

Edited December 11, 2024 by BlueTR3A-5EKT

[PodOne]

As you say Charlie it’s mostly common sense I’ve re wired all my previous houses in part or fully and had them signed off Part P regs. So hopefully no reason for insurance company not to pay out. My understanding is that you are still allowed to extend/spur from a ring main on a DIY basis. 
 

My thoughts were that it’s better for a dedicated 16A supply to come from the consumer unit which is split into 4 sections upstairs, downstairs, office and garages all with isolation etc.

The new old stock Red and Black twin and earth is much thicker gauge than the modern 2.5  stuff. Left over from my dad who was a sparky many moons ago but take your point might be better to match modern colour coding and find someone prepared to sell me a couple of meters not 100m!

Andy

 

[Charlie D]

1 hour ago, PodOne said:

...My understanding is that you are still allowed to extend/spur from a ring main on a DIY basis...

That was my understanding of the regulations as well, but I thought that going inside the consumer unit to do wiring was deemed beyond the DIY skill set and you had to get an electrician to do it.

However...

I'm sure I read here somewhere that if an electrician has to do ANY work on a consumer unit, and that consumer unit was made of plastic, the whole unit has to be replaced by a metal one.

So a £100 job to add a new 16Amp socket could end up as  £500 job to replace the consumer unit.

Never ending is it...

Charlie

[RobH]

51 minutes ago, Charlie D said:

So a £100 job to add a new 16Amp socket could end up as  £500 job to replace the consumer unit.

....and if the house wiring is an older installation he may also find the lighting circuits have no protective earth nor RCDs, so do not conform to the latest requirements. Any change to an existing installation requires the whole lot to conform to latest regulations before he can issue a certificate, so the lighting circuits and fittings may need to be replaced too. £££££ !

A friend of mine was caught like that when he had a car charging socket installed. 

 

Edited December 11, 2024 by RobH

[RogerH]

Many many moons ago when those swish 1KW infra-red single bar electric heaters became available we had one in the bath room.

It was plugged into the ceiling light two pin socket which dangled over the bath.

It was nice and cosy but god only knows what could have happened.

Thankfully there was no ELF and Safety at the time so we were OK.

The rest of the house did not escape - we had the TV also plugged into a ceiling light socket.

Thankfully the gas cooker didn't need leccy

 

Roger

[RobH]

2 minutes ago, RogerH said:

It was plugged into the ceiling light two pin socket

Back in the  '50s my mother used to plug her metal-bodied electric iron in like that .   She also had a bit of asbestos sheet on the ironing board to rest the iron on. 

I seem to remember some of the house wiring was rubber insulated and lead sheathed.........  

[stuart]

1 hour ago, RobH said:

Back in the  '50s my mother used to plug her metal-bodied electric iron in like that .   She also had a bit of asbestos sheet on the ironing board to rest the iron on. 

I seem to remember some of the house wiring was rubber insulated and lead sheathed.........  

First house we had was like that, one round pin socket in the lounge and nothing else. Upstairs was a two small round pin socket. Missus used a "Y" adaptor in the light socket in the kitchen with the iron on one side and the light bulb on the other..

Stuart.

Edited December 11, 2024 by stuart

[RogerH]

Happy memories  

[Charlie D]

In the 1970s my wife and myself used to live in a flat where the bathroom, toilet and kitchen were all in one small room.The cooker was an ancient rusting Baby Belling electric job and it was possible lay in the bath and open the oven door to see how the Sunday lunch was going.

My wife frequently used an electric hair dryer whilst in the bath.

It's funny how all of us of a certain age just took it all for granted.

[Ian Vincent]

On 12/11/2024 at 9:57 AM, RobH said:

Well in view of recent events in America, that does seem to be the case.  They have caught the (alleged) assassin though. 

Interestingly, well to me anyway, according to the article I read, the alleged assasin is only being charged with second degree murder which I understand to be for 'Opportunistic' killings as opposed to 'Premeditated' or first degree murder.

I struggle to understand how someone who assembles a gun from various bits bought on the internet along with a 3D printed body and then travels from his home in Pennsylvania to New York to creep up behind someone and shoot them multiple times can only be guilty of opportunistic murder.

Strange place the USA.

Rgds Ian

[Phil Read]

On 12/11/2024 at 12:55 PM, RobH said:

....and if the house wiring is an older installation he may also find the lighting circuits have no protective earth nor RCDs, so do not conform to the latest requirements. Any change to an existing installation requires the whole lot to conform to latest regulations before he can issue a certificate, so the lighting circuits and fittings may need to be replaced too. £££££ !

A friend of mine was caught like that when he had a car charging socket installed. 

 

You can get round this by leaving the old curcuits as is and have a separate installation with its own RCD. I have had 2 extensions on my house, the original house is on the old system and each extension (done at different times) has its own RCD and RCCB.

[Trumpy]

On 12/10/2024 at 9:38 PM, PodOne said:

Calling any electricians.

About to take delivery of a LGX35 3500kg lift with a 16amp plug.

It needs a 240v 16 amp C rated MCB. The motor/pump is rated at 2.2kw.

Do I need a 16amp 6KA or 10KA one?

Thanks

Andy

Surely a 2.2 kw motor will only draw 9-10 amps and only for a short period of time. 
why not just swap the plug for a normal 13amp and use an existing socket ? 
No doubt already sorted by now tho’ 

[RobH]

20 minutes ago, Trumpy said:

Surely a 2.2 kw motor will only draw 9-10 amps

Yes that is the continuous running current once the motor has reached operating speed but induction motors pull a current surge as they start up, which is higher than the running current and which could easily be twice as much.   Also, being an inductive load, the power-factor will give an out-of-phase current which can be rather higher than you would expect from a simple Ohms law calculation  (though the PF is dependent on the type of motor and varies with load).   i.e. a motor with 0.7 PF will draw 1.4 times the current you would expect from P=VI, so in this case the actual motor current could easily be 14A.

 Industrial sockets are built to withstand this sort of use on a regular basis so are more suited to this type of application than a domestic socket. 

[Trumpy]

Sure all you said above is correct and I appreciate the higher start up load but at just 2.2 kw there is plenty of spare capacity . 
Also the lift is rated at 3500kg which would load the motor to its max . 
An 1100kg Tr will not load the motor any where near as much .( I couldn’t imagine anyone lifting a 3.5t truck on a scissor lift . ) 

My lift is also rated at 2.2kw and it works fine on a 13amp plug / supply . 
If it was me I would certainly swap the plug and try it .  If the breaker trips then spend the money on a new supply . If not then sorted ! 
An electrician could easily measure the current being drawn for peace of mind . 

 

[RobH]

30 minutes ago, Trumpy said:

An 1100kg Tr will not load the motor any where near as much

2.2kW inductive load is a different case to 2.2kW resistive and it is at lower loading that the motor PF is worse - though as I said that depends on the motor and the control circuitry.  

I'm not saying it wont work on a 13A plug - just that it may not be ideal and the plug could be overloaded under certain conditions.  It isn't as simple as it seems from Ohms law. 

 

[PodOne]

Update.

I've kept with a 2.5 mm twin and earth supply taken from the consumer unit to a 16amp socket to match the supplied plug and not void the warranty (you know what they are like if you mess with things!). 

The 16A C rated MCB breaker initially tripped with no load I suspect due to the lack of grease to the slider blocks and the overall friction of it being new. A good greasing and it still occasionally trips with no load again I suspect due to the friction of every thing still bedding in.

So for now I've replaced with a 16A D MCB. No tripping with no load and the ramp is going up and down much quicker now. For now I've and made some run up ramps to negate the need to cut out the floor.

Finally need some steel rectangular box section to make some spreader bar to pick up the chassis at the front. Anyone suggest what gauge to take the weight of the TR with a safety margin?

The ultimate test will be with the cars full weight on it but I think it will be fine 

Thanks

Andy 

  

[james christie]

My cross pieces are rectangular tubing, from memory - I'm currently the otherside of the country - something like 60mm x 35mm, which is probably serious overkill.

I went down the same road as you initially and like you built up some ramps, but they so exasperated me that I finally bit the bullet - and the dust - and sunk the whole thing level with the floor and recuperated the whole garage surface area.

I'm more than pleased with it - so are my neighbours and some folks that I'd never met before!

james

[Trumpy]

I’ve used 50x50mm box x 2mm . Again a bit over the top but I had some . 
As shown in the pic I welded some heavy angle on both ends to drop the box / beam level with the ramps and allow it to slide forwards / backwards and it lives on the ramp . Also added sliding plates to jack / lift from .  
works really well . 
 

[PodOne]

20 minutes ago, Trumpy said:

I’ve used 50x50mm box x 2mm . Again a bit over the top but I had some . 
As shown in the pic I welded some heavy angle on both ends to drop the box / beam level with the ramps and allow it to slide forwards / backwards and it lives on the ramp . Also added sliding plates to jack / lift from .  
works really well . 
 

Perfect solution but I don't think I'd fully trust my welding skills!