240v 1ph Motor running backward's.

[Grizzly]

On commissioning a 2 fan condensing unit which has 2 x 1.7amp FLA single phase fans.
Both fans came pre wired with a start capacitor already fitted.
All that was necessary was to provide a single phase supply to each.
Both fans run back wards causing a down draught through the Condenser.
Rather than up through the Condenser as is required.

Has anyone come across this before?
And has anyone any suggestions?
Thanks Grizzly

[Gary]

On commissioning a 2 fan condensing unit which has 2 x 1.7amp FLA single phase fans.
Both fans came pre wired with a start capacitor already fitted.
All that was necessary was to provide a single phase supply to each.
Both fans run back wards causing a down draught through the Condenser.
Rather than up through the Condenser as is required.

Has anyone come across this before?
And has anyone any suggestions?
Thanks Grizzly

Are you sure those are not run capacitors?

[monkey spanners]

I think they should go:

Live motor-live
Neutral motor,cap-neutral
Start-cap

I suspect you have

Live motor-live
Neutral motor, cap-
Start-cap, -neutral

This makes the run winding now the start winding and makes the motor run backwards.

Jon

[Gary]

Without the capacitor, the motor doesn't know which way to turn. The first puff of wind that comes along will determine the rotation. Check the capacitor wiring.

If these are in fact start capactors, the motor could be wired wrong (run and start swapped).

[chemi-cool]

Hi Grizzly.

Electrically its easy, all you have to do is change the wires of the main winding with the start winding.

Or, They could have been fans with the wings pushing the air.

And as Gary said, its a run capacitor.

[Grizzly]

Hey Guys
Thanks for the input.
I will check out what type of capacitors they are and let you all know.
Basically as I said they were both
Pre-wired and just requiring a 1ph supply.
There is a second Condenser to be wired up next week.
Both brand new and just out of the box.
Straight from the suppliers in Italy!
I will compare the 2 units next week.
I have been cautious so far because of any deemed warranty issues.
Your advise is good and it's a possibility that the issue could be resolved locally.
I cannot believe both units would be at fault?
Hey! We shall see.
Once again thanks so far to all!
Grizzly

[salamander]

On single phase motors, you need to switch two of the nine wires from the motor. I would have to look at my cheat sheet. This is not like 3 phase, where you change two power legs. The nameplates or pecker head covers should show cw or ccw wiring diagrams. If you can't rewire, maybe you could flip the fans.

[Grizzly]

Salamander.
Thanks for your input.
The 9 wire system does not exist on this motor and turning the fans over.
Is not possible on this type of condenser.
For further clarification to all those interested.
Please see the attached schematic showing the required supply connections.
Cheers Grizzly

[Peter_1]

You should check the fan blade to see if it's a blown through or a suck through type. Changing the wiring like Chemi said will change the rotation direction but a fan blade can only run in one direction.
You can see this in the curve of the blade shape.
Perhpas they fitted the wrong fans.

[B G Scott]

On commissioning a 2 fan condensing unit which has 2 x 1.7amp FLA single phase fans.
Both fans came pre wired with a start capacitor already fitted.
All that was necessary was to provide a single phase supply to each.
Both fans run back wards causing a down draught through the Condenser.
Rather than up through the Condenser as is required.

Has anyone come across this before?
And has anyone any suggestions?
Thanks Grizzly
If you can via the terminal box identify all the wires going to the ends of the start and run winding, identify the start winding and change the rotation by interchanging the wires going to the start winding.Retain the set up for the run winding
As these are fan motors I am assuming these are PC (permanent capacitor motors)

[Grizzly]

You should check the fan blade to see if it's a blown through or a suck through type. Changing the wiring like Chemi said will change the rotation direction but a fan blade can only run in one direction.
You can see this in the curve of the blade shape.
Perhaps they fitted the wrong fans.

Thanks for the advise Peter.
Rotation and blade pitch was one of the things I first checked.
Mainly to, as you suggest confirm the required fan rotation.
The indicated rotation, blade curvature and Manual all indicate Up draught as I said.
Not downdraught from top to bottom as I have.
Thanks to everyones help I have plenty to go on.
But I will have to wait until the manufacturer / supplier has been contacted.
Before I adjust anything, so as to not invalidate any warranty.
I should know more next week and will advise accordingly!
BC thanks for your helpful advise also.
cheers Grizzly

[Peter_1]

Blade curvature, that was the word I was looking for.

[jimbo82]

B G Scott is right - swap the two ends of the start winding. This will cause the magnetic field to be in the opposite direction making the motor spin the right way. The start winding sometimes has thinner gauge wire. I assume going by your diagram that this motor has a thermistor fitted and the terminal between live and neutral has 2 wires in it?

[jimbo82]

Seeing I can't edit my post above sorry I assume the Neutral terminal has 2 wires in it? Not the centre terminal.

[Grizzly]

Seeing I can't edit my post above sorry I assume the Neutral terminal has 2 wires in it? Not the centre terminal.
Jimbo.
Thanks for the input!
Like I have said earlier. I will be able to confirm what is what next week.
Last week apart from confirming the direction of rotation and correct attachment of the incoming Power cables.
The fans were not touched.
All the same thanks for the help.
Grizzly

[goshen]

Thanks for the advise Peter.
Rotation and blade pitch was one of the things I first checked.
Mainly to, as you suggest confirm the required fan rotation.
The indicated rotation, blade curvature and Manual all indicate Up draught as I said.
Not downdraught from top to bottom as I have.
Thanks to everyones help I have plenty to go on.
But I will have to wait until the manufacturer / supplier has been contacted.
Before I adjust anything, so as to not invalidate any warranty.
I should know more next week and will advise accordingly!
BC thanks for your helpful advise also.
cheers Grizzly
Hi there still waiting ,what was the turn out ???
which manufacturer are we talking about?:p

[glenn1340]

Hi Grizzly,
I`ve had the same problem, I fitted a condensor fan with a capacitor only to have the same problem as you: the wrong rotation. I checked and checked again the wiring diagram. Now, I recently went to a job where the same make and type of fan is used but that too is running the wrong way. It`s due for replacement as the bearings are shot so I`ll see if the new fan has the same problem.

[Grizzly]

Hi Goshen and Glenn.
I have not replied yet because the 2nd set of fans have yet to be powered up, which is due to happen Tuesday.
Once they are confirmed as correct the original pair will be modified.

Basically when wiring these motors up it was assumed that they were to the new European Harmonised wiring standard as they are Alpha Laval.

As there are Blue, Brown and Black wires within the Motor.
Where Brown is Live, Blue is Neutral and Black was a common.

The wiring diagram within the motor terminal cover was initially not noticed.
Because the cover screws were loose and as they could potentially drop into the condenser.
The covers were carefully place upright out of the way whilst wiring the fans up.

This is how they are actually wired up:- (As Instructed by the OEM Tech Support Team)
Cable Motor
L to Blue
N to Black
Discuss!

Even when the wiring diagram as previously attached was referred to it is not exactly clear.

Anyway lesson learnt and just maybe it may help someone else in the future.
Credit to all the guys answering this post and thanks once again Grizzly.

[Grizzly]

Hi Guy's.
Yep! Problem resolved.
Wiring up the motors as Blue Live and Black Neutral, resolved the problem.
Not only are both sets of fans running in the correct direction.
But they are an awful lot quieter.
Thanks Grizzly

[chemi-cool]

Hi Grizzly.

Electrically its easy, all you have to do is change the wires of the main winding with the start winding.



Told ya....;)

[monkey spanners]

Told ya....;)

Me too! ;)

Jon :D

[chemi-cool]

Me too! ;)

Jon :D

OK, OK.......A pint for you as well..;)