Converting spray booth from 3phase tp 240v

[bert]

At work we have just bought a dalby 8k spray booth that has 3phase motors.

Our unit doesn't have 3 phase and the cost of a 7.5kW converter is a bit much so the boss is stuck with buying a 3phase generator.

How hard is it re rewire to 240v as the motors aren't that expensive to replace.

Thanks

 

[500e]

Want a generator ??

 

[bert]

Probably, if so how much and what ls it's specs?

 

[carbon]

It would depend on the coil voltage of any contactors used. If they use 24v switching then it’s a possibly that they would be suitable but contact ratings would need to be checked before making any changes. Also motor overloads would likely need replacing as a minimum

 

[winchman]

Firstly I suspect a 240v motor may not be a direct swap and as mentioned the overloads, cables etc would need changing, as its a spray booth its classed as LEV I would assume so must work within certain parameters and be tested, if you fit the wrong motors it may not pass another test?
First job talk to Newton Tesla in Warrington as they may be able to sell you a drive at a more competitive price, they do repairs so may even have a used one.

Newton Tesla | Mitsubishi Electric Products, Motors & Gearboxes

Newton Tesla are the leading supplier of Mitsubishi Electric products | Providing Electric Motors & Gearboxes in the UK | Contact us or Order yours today.

www.newton-tesla.co.uk

 

[bert]

So.this is the inside of the control panel, everything seems to be 240v spec to me but I don't really know much about this.

We have been told we need a 15kW 3phase converter to run the booth.

Any ideas as the converter is £3k.

I'm of the opinion converti g to 240v should be cheaper than that.

 

[bert]

 

[Chippie]

Looks a bit dusty in there….!!

Whats with the black box at the bottom with the plastic piping?

 

[bert]

Something to do with air pressure in the booth

 

[carbon]

I’m only looking at this on my phone. You need to know the coil voltage of the three contactors marked in yellow and what is the device marked in blue. Can you add better pictures of those two areas as well and any markings on the timers to the right of the contactors

 

[carbon]

Looking at this again some of the panel may be using 240v as there is a neutral connection at the isolator(black wire) and the right hand contactor is only switching two of the phases, but through separate breakers. Does this booth have two motors?

 

[carbon]

Looks a bit dusty in there….!!

Whats with the black box at the bottom with the plastic piping?

I think spray booths check to pressure drop across the filters to give an indication of when they need replacing or give an indication of airspeed through the filters

 

[bert]

Looking at this again some of the panel may be using 240v as there is a neutral connection at the isolator(black wire) and the right hand contactor is only switching two of the phases, but through separate breakers. Does this booth have two motors?

Yes 2 motors, one for the burner and one for the extraction.

I'll have to check on the yellow marked one as the part number is generic and nor for voltage.

The blue one is 240v

The burner ignitor is 240vac as is the lighting but it's taken from the 3 phase as there is no 240v supply into the box.

 

[bert]

I think spray booths check to pressure drop across the filters to give an indication of when they need replacing or give an indication of airspeed through the filters

Yes it's so you can tell the booth is in negative pressure when running = filters are not blocked

 

[carbon]

The burner ignitor is 240vac as is the lighting but it's taken from the 3 phase as there is no 240v supply into the box.

There is, the neutral and one of the phases provides 240v. As two phases are switched with the third contactor I assume they are spreading the single phase load across the phases.

 

[bert]

Close up pics of the bits in the control cabinet

 

[carbon]

The smaller relays have 240v coils, can’t see any markings on the two timers for voltage but unlikely to be 415v.

How big is the motor?

Looking at the wiring the two motor overloads are wired in parallel.

Does it have a star delta start motor?

 

[minimutly]

The smaller relays have 240v coils, can’t see any markings on the two timers for voltage but unlikely to be 415v.

How big is the motor?

Looking at the wiring the two motor overloads are wired in parallel.

Does it have a star delta start motor?

240v controls - there's no control transformer. Likely all the coils will be 240V then. Fit 3 inverters, one for each fan, fed from the contactors, days wiring, and setting up?
Edit to add - Ooo, there's a differential pressure switch - is that to give an alarm or to switch the fans off if someone opens the door?

 

[carbon]

Fit 3 inverters, one for each fan

I think it’s only one fan

Yes 2 motors, one for the burner and one for the extraction.

A picture of the extraction motor data plate and the burner would help. Is the burner three phase or single?

 

[minimutly]

So.this is the inside of the control panel, everything seems to be 240v spec to me but I don't really know much about this.

We have been told we need a 15kW 3phase converter to run the booth.

Any ideas as the converter is £3k.

I'm of the opinion converti g to 240v should be cheaper than that.

Cost wise 2 (thought there were 3 fans initially) inverters at £200 a pop, plus the work to fit and set up.
Or, buy some single phase motors and fit to the fans, again £200 a pop, plus a bit less time to mod the panel.
A lot cheaper than a phase converter (which would likely not be happy with the off/on nature of the loads.
what are the brown cores at top left? Lights?