running a 3 phase fryer from a 1 phase supply

Thread Starter

valeyard93

Joined Oct 24, 2020
5
Asking for some advice as I can't seem to find anything. I have been asked if there's any way to run a 3 phase fryer from a single-phase supply. I've attached some images below.

20201024_142134.jpg20201024_132959.jpg

any idea for rewiring would be appreciated

I looked at a variable frequency drive but to my understanding, it won't work as there is no motor.

Kind regards.
 

MaxHeadRoom

Joined Jul 18, 2013
21,629
That unit is rated for 400-415v 3ph, what 1 phase supply do you have available?.
If that unit consists mainly of heating elements. they are each going to be 1ph anyway, but spread across three phases.
There is most likely some L.V. control in there, of some kind.
Max.
 

Delta prime

Joined Nov 15, 2019
576
Hello there :)
TS said "I have been asked if there's any way to run a 3 phase fryer from a single-phase supply". Rotary Phase Converters run on single phase power and generate 3 phase to power your equipment. Rotary phase converters rectify single phase AC power into DC then invert with proper phase angles Determining the 3 phase starting load of your machine will help your fryer is a resistive load rather than inductive. It is all
About cost. My superior Mr.Maxheadroom
Can save you more money than me.
 
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Thread Starter

valeyard93

Joined Oct 24, 2020
5
That unit is rated for 400-415v 3ph, what 1 phase supply do you have available?.
If that unit consists mainly of heating elements. they are each going to be 1ph anyway, but spread across three phases.
There is most likely some L.V. control in there, of some kind.
Max.
Thanks, it has 3 elements, each element runs of 1 phase each as you described. just domestic electrical circuit atm but it will be used in a certified food marque, I suspect drawing power from different places. It might just be worth keeping as 3 phase and hope they have the 3 phase connections. the people just thought it would be better as a single-phase if they wanted to cook from their home too.
Just to be clear; It was built for 3 phase 400 volt and you want it to run on 1 phase 400 volts? The question is 400 volts?
yes built for 3 phase 400v, I was just wondering if there's any way such as converter or converting the wiring so it would be possible to run it from a 230v single phase domestic supply. the person who asked me is adamant there is a way to do it and said he's seen it done. I cannot think of a way but I'm not too familiar with 3 phase supplies.
 

ronsimpson

Joined Oct 7, 2019
1,017
Need more pictures. (different angle) Where are the heating coils?
There are 6 connections in the center that look like heating coils. Red arrow.
On the right side there are, something I can not tell what it is. Red arrow.
There are two "?" in red. I think one is a switch.
1603552959180.png
I think it is easy to convert, but more information/pictures.
 

ronsimpson

Joined Oct 7, 2019
1,017
The 3 to 1 phase is easy. The 400 to 230 that is not easy. But in several projects I found that the elements are actually two 220V elements in series to make one 440 element. Rewiring from series to parallel works. (do you feel lucky)
 

MaxHeadRoom

Joined Jul 18, 2013
21,629
It appears your unit has a neutral which indicates that if so, the individual elements are each 240v, which means that you can parallel the elements for 240v 1ph but you will need a high enough capacity supply for this large wattage.
The 16a value per bank confirms it.
Max.
 

MaxHeadRoom

Joined Jul 18, 2013
21,629
Simple if you have 240v AC 1ph supply, you just need the current capability for 3 banks in parallel.
There have been previous enquiries of the same nature a few times here.
Max.
 

Thread Starter

valeyard93

Joined Oct 24, 2020
5
Need more pictures. (different angle) Where are the heating coils?
There are 6 connections in the center that look like heating coils. Red arrow.
On the right side there are, something I can not tell what it is. Red arrow.
There are two "?" in red. I think one is a switch.
View attachment 220489
I think it is easy to convert, but more information/pictures.
yes the arrows are the elements there are 3 stacked on top of each other the bottom 3 are the live the top 3 the return live/ neutral. the top 3 all connect together.
L1 blue wire from supply connects to the green light and top element
L2 goes to the middle element
L3 goes to the temperature dial (the orange box on left) and bottom element, also the small black box below the white box with the question mark.

The white box connects to a switch (20201024_163244.jpg ), I believe then the element fits to the rest of the fryer the button is depressed to create the connection and thus disconnects then the element and electrical parts are lifted apart. from the fryers "baths"

the bottom electrical box (20201024_163251.jpg) seems to be a Rational contactor K1- 09F00


thanks
 

Attachments

Thread Starter

valeyard93

Joined Oct 24, 2020
5
Just do the math, you have each bank 4kw at 16a/bank which means that each bank is 240v which is what you have on a 415v 3ph supply from phase to neutral.
Max.
thanks very informative, so it should be easy enough to wire in parallel as long as the device can draw enough current from a high rated fuse?
 

MaxHeadRoom

Joined Jul 18, 2013
21,629
It appears you parallel the three phase incoming connections, take the 240v 1ph supply to this point and supply a neutral.
I would guess the 3phase is switched by the contactor, and the un-switched neutral common to each.
You can trace the circuit out of each bank to confirm this first.
You would need a 50a - 60a 1ph supply
Max.
 

Thread Starter

valeyard93

Joined Oct 24, 2020
5
It appears you parallel the three phase incoming connections, take the 240v 1ph supply to this point and supply a neutral.
I would guess the 3phase is switched by the contactor, and the un-switched neutral common to each.
You can trace the circuit out of each bank to confirm this first.
You would need a 50a - 60a 1ph supply
Max.
Thank you, you have been very helpful. yes, the neutral is all linked. Each phase is linked and switched by the connector.:)
 

Marc Sugrue

Joined Jan 19, 2018
167
Easy answer is you shouldn't. It was done as 3 phase to share the load and keep sensible currents onto the power distribution and prevent cables from overheating and becoming a fire hazard. Unless your a electrician with full knowledge of the building and wiring regulations, not to mention knowledge of the domestic wiring at the location for installation. Don't do it
 

ronsimpson

Joined Oct 7, 2019
1,017
I drew green lines across L1, L2 & L3. Last time we did this, just connect L1,2,3 together, and connect to one leg of 220. What was neutral will now be the other 220 wires. Changes could be made in the power cord.
1603566789043.png
 

MaxHeadRoom

Joined Jul 18, 2013
21,629
You would need a minimum of 6AWG cable.
Often when 1ph loads similar to this such as large furnaces, the elements are brought on line one at a time to cushion the inrush.
You don't say where you are, but N.A. is pretty much all 240v 1ph now.
Max.
 
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