Compressor 3-Phase wiring

[tona955]

Hi All,

I am trying to connect my 3 phase compressor to the supply.
Could someone confirm the terminals to use are L1, L2 and L3 plus teh stud ground and not the T1, T2, T3.
I iwll try to attach a picture on the connector block and my supply switch.

Many thanks in advance

 

[knighty]

it's a bit tricky to see which wire goes where by the pictures

it looks to me like your power should be wired into bottom of the 3 left most din rail connector blocks - the ones with wires number 3, then 4, then? going into them (the beige ones just to the right of those two big contactors)

there's a couple of wires coming out the bottom of those already... see where they go and post back ?

tops of those connector block thingies wire straight into the contactor on the left.. but there's a couple of other wires in contactor too... where do they go ?


does it have a big fan or something attached to it ? - I'm wondering what the other contactor is for, and the timers etc.. (unless it's been changed around over the years... maybe it used to be star delta etc.. (starts on low power for 1 few sec to get it going before it goes full power)

 

[tona955]

Many thanks for your response.

Its a Hydrovane HV07RS screw compressor buddy, I have attached the wiring diagram I got from the dealers and hop that it helps better.

 

[tona955]

Sorry meant to say, There is a box on teh outside with the power on/off switch, this is where the green blue and wires go to.

 

[knighty]

ahh, 2nd contactor is cooling fan

ok, those L1, L2, L3 connections you circled in your first picture

they should be wired over to the beige connector blocks just to the right of the contactors
and they should also be wired into the top of the next contactor

if that's right, your 3 incoming positives go to the bottom of the beige connector blocks


don't want to teach my granny to suck eggs but do you know to check phase rotation ? (and how?)

easiest (a little cheat) is, if you just wire it in you have a 50/50 chance it'll spin the right way... so wire it in, turn the power on for it, but don't turn the compressor on

the contactor 2nd from left is for the cooling fan... when those power on the center pulls and makes contact between the top and bottom connections.... with a testing screwdriver (or some kind of safe one so you can't get a shock if you slip)... push the middle of it in - push it right at the top, the little white bit in the middle left of the add on connector (the bit with yellow wire in the top red out the bottom)

then the cooling fan will spin.... have a look and see if it's spinning the right way

if it is you're all sorted, put all the covers on and have a cuppa

if it spins the wrong way, turn the power off and swap any two of your positives... it doesn't matter which two you swap or where they're connected, just swap them

now it'll spin the right way :-)

(but power up the fan again, always nice to be sure before you power up the expensive hydrovane!)

 

[tona955]

Hello again,
Many thanks for your quick response, you are infact not teaching your granny how to suck eggs buddy, I have carried out house wiring projects before but the 3 Phase I do not know and I'd rather be safe.
Thank you again for the cheat, as you say I do not want to damage this expensive compressor. I will try to get this done over the holidays and report back, If I get unsure about anything I shall get in touch.
Have a Lovely Xmas and a happy new year

 

[knighty]

no worries at all, I'm glad to help :-)

 

[tona955]

Just a thought, I bought the compressor on eBay from a good car dealership. They had this working till their new upgrade...that being the case I would have thought any jumper wires should already be installed and all I neex do is wire up my supply..just 4 wires.

It that reasonable to assume?

 

[daleyd]

The cooling fan looks like it’s single phase, so you shouldn’t get the direction wrong.

If it’s come complete then I would have thought you should just connect your 3 phase up to the incoming terminals like you say - probably be wise to go through the drawing and tick off the wires that are connected and mark them off so you know you aren’t missing anything.

 

[tona955]

That was my thoughts also.
So to recap, I just need to connect my incomming supply to the bigger left most terminal block labelled...L1 L2 L3 etc.

 

[daleyd]

I’d say so, but have a good double check with your diagram, especially to ensure nothing has been left hanging out.

If something’s disconnected then the worse that happens is it just won’t start, what you don’t want is to find a wire hanging out!!

 

[knighty]

wiring diagrams are for a single or 3 phase cooling fan, photo of the wiring makes it look like it'll be 3 phase

the bit with L1, L2, L3 on it is a contactor (like a bit relay)

to the right of that there's another smaller contactor, and to the right of that some connector blocks - that's where you need to wire in to

you could wire into L1,L2,L3 but then the wires might be a tight fit, you'll need to check a couple of bits etc... easier just to wire into the connector blocks where it was wired into before


I edited/attached a picture

 

[knighty]

EDIT: easier to wire into the bottom half of those tho... my red square should have been a bit lower!

 

[daleyd]

Yes, it looks like those terminals were where it was wired to originally, so use those.

The drawings don’t seem to match up completely as they both show single phase fans but the wiring doesn’t seem to match, it may have had a 3 phase motor fitted at some point. The drawings also show a vfd fitted for the main motor.

 

[WorkshopChris]

Whats on the end of the six grey singles and the black flex?

 

[knighty]

6 gray singles are the motor windings - 6 to give you the potion of a star delta starter

 

[daleyd]

Something doesn’t tie up with those drawings then - they don’t show that (they show a vfd) and that second contactor may not be for the fan but the other contactor for star/delta operation.

Plus those 6 singles come out of 3 terminals - it’s been a while since I’ve done anything with star/delta stuff but I thought they would have their own terminals?

 

[WorkshopChris]

I was wondering if everything in the box was obsolete and they were running a vfd tapped in via the black cable. ( Only one Fuse in the control power transformer) lots of changes from original. Need some more digging from the op.

 

[normspanners]

but the other contactor for star/delta operation.

6 gray singles are the motor windings - 6 to give you the potion of a star delta starter

cant be the position of the star/delta starter coz those 6 singles come out of 3 terminals and it cant be star /delta with 3 connections

I was wondering if everything in the box was obsolete and they were running a vfd tapped in via the black cable. ( Only one Fuse in the control power transformer) lots of changes from original. Need some more digging from the op.

Those are my thoughts too,
at first glance I thought star delta especially with the timer etc but only 3 wires to 6 motor wires but there is no variable speed drive in there as per either of the diagrams.

 

[daleyd]

cant be the position of the star/delta starter coz those 6 singles come out of 3 terminals and it cant be star /delta with 3 connections

Yes thats what I said in the next paragraph.