Electrician Jobs Three Phase Rotary Converter Install with Sockets

[Jacob Porter]

Not a 'commercial' job as such but given that three phase is involved I feel it belongs in this section.

In my semi-professional cabinet making workshop I have a 32A consumer unit. For a range of three phase machinery I have acquired a Transwave Rotary Converter (RT4) which requires a 25A breaker. The converter is sitting on a shelf in the workshop but I need it wired in to the consumer unit and then I need 4 sockets round the workshop. The 'shop is very small, maybe 3mx5m and the cable distance of the workshop consumer unit to the kitchen consumer unit is less than 20m.

If you are happy for me to, I can install any conduit/plywood backing for any hardware to attach to as I'm looking to contain the costs of this job

I would also like plugs attached to at least one, maybe two (will check when I'm home) machines.

If three phase electrics is something you have experience with please let me know when you can do this and a guide price based on the information required or if more info is needed.

 

[Strima]

As the converter needs a C type MCB the start up current may be over the operating threshold of the 32 amp supply device.

Also, dependant upon wiring type and installation method, your supply cable may not be of a suitable size to meet disconnection times for the new installation you want.

You would need a visit from an electrician to discuss and design what you need, hopefully a forum member is in your local area and able to help.

 

[Jacob Porter]

As the converter needs a C type MCB the start up current may be over the operating threshold of the 32 amp supply device.

Also, dependant upon wiring type and installation method, your supply cable may not be of a suitable size to meet disconnection times for the new installation you want.

You would need a visit from an electrician to discuss and design what you need, hopefully a forum member is in your local area and able to help.

Thanks Strima, I was hoping that wouldn't be the case as I only laid the cable down last year and it took me forever to dig that trench it's buried in, then to patio over it

I'm guessing it's type C. On start up current I found this in the transwave documentation:

"The full load running current (f.l.c.) of an induction motor operating on a single-phase supply is
approximately four amps per hp. When operated in conjunction with a TRANSWAVE Converter, the
starting current of a three-phase motor is limited to approximately 3 times its f.l.c. This is significantly
lower than the motor starting current of an equivalent sized single-phase motor, which would typically
draw between 6-8 times its f.l.c."

My largest individual machine is 4hp. This would equate to a start up current of 48A. (33% larger than the cable is rated for)

Is this likely to be a steady state rating or an instantaneous surge rating?

EDIT: The documentation also states that a 4.0mm input cable is required for 240V Single Phase side

EDIT2: Reading back my invoice for last year's install of the circuit I have a 4mm cable

 

[Strima]

There's a lot more to designing a circuit than the current rating of the cable.

For example voltage drop on your cable may be sufficient when no machines are running, however when one starts this could cause sufficient voltage drop to dim your lights possibly causing damage and/or plunging you into darkness, not what you want when things sharp things are spinning quickly...

 

[Jacob Porter]

We're drifting slightly off topic here. I'm not trivialising the designing of a circuit - I've clearly said I would like the electrician who takes the job to do that. If I were capable of designing this circuit, and comfortable implementing it, I wouldn't be here in the first place.

Is there anyone viewing this thread who can quote for this or suggest someone that can? Or even give a guide price based on the knowledge available?

 

[Jacob Porter]

I'll rephrase the above:

Is anyone available [to come round and quote this because they are interested in the job] or give a guide price [based on their experience of similar jobs because they are too far away/the job is too small for them to do but might be able to help me so I know what to expect].

Did I come to the right place?

 

[westward10]

You have come to the correct place so someone may be interested but give it a bit of time.

 

[Pete999]

You have come to the correct place so someone may be interested but give it a bit of time.

"Westward 10 s post" yes you have come to the right place for help Jacob, it's to far for me to come to help but as Westward said give it some time, remember a great deal of the members, are at work away from their devices, it's Friday so give it an hour or so for the members to finish work, have their evening meal, and with luck someone will be in touch with you, patience my Friend patience.

 

[westward10]

I have tidied this thread up so only the relevant bits are in place.

 

[marconi]

Jacob Porter - if you PM me I will provide contact details for an electrician who might be interested in doing the work - the one I use based in Dagenham.

 

[Jacob Porter]

Hi all,

still looking for an electrician with experience in three phase circuits