PDA

View Full Version : Differce of 50 hz and 60hz



jaison
20-06-2007, 07:50 PM
Hai engineers,
How is the after effect if 50 hz compressor work in the 60 hz 220 v suplay, also 60 hz in 50 hz suplay . Thanks.

The MG Pony
20-06-2007, 08:10 PM
there is 10Hz difference! :D

Or rather the 50Hz compressor will run faster on the 60Hz the inverse is true as well; A 60Hz compressor will run slower on a 50Hz supply and capacity will fluctuate along with rotational speed.

Toosh
21-06-2007, 09:06 AM
Hi First of all Compressor manufacturers make dual voltage Compressors thus they can be run on 50 or 60 Hz depending which area the instalation is.

Toosh

norseman
21-06-2007, 12:04 PM
Hai engineers,
How is the after effect if 50 hz compressor work in the 60 hz 220 v suplay, also 60 hz in 50 hz suplay . Thanks.
I am working a lot with 60hz compressors from USA
here in Norway and find that the maximum voltage often is rated lower on 50hz. The compressors takes more amps due to the lower speed. The Copelands I use in cascade systems are rated 208-230v 60hz and only 200-220v at 50hz.
:)

frank
21-06-2007, 08:02 PM
We had a real bad time with the solid state cam timers on some Y**k air cooled condensers some years back.

Apparently, the units were made in the USA then shipped over to France where they were rewired to comply with local regulations.

It transpired that the timers were rated for 60hz and couldn't operate properly on the UK electric supply??

Well, thats what Y**k said.

P.S.

Haven't touched ANY Y**k kit since - back up was less than helpful.

I've got some photo's somewhere of the wiring, I'll dig them out and post them - should cheer you up :D

frank
21-06-2007, 08:26 PM
Attached Photo

Note the old ICI R22 cylinders

Brian_UK
21-06-2007, 10:04 PM
http://www.refrigeration-engineer.com/forums/attachment.php?attachmentid=1597&d=1182453992
As the service manager said, "Just do a bit of fault finding, the Y**k manual and drawings should be on site."

Yeah, right.

Just follow the white wire from the hidden sensor ;)

jaison
22-06-2007, 09:03 AM
Have any way to run 60 hz compressor on 50 hz suplay at normal amps.

Electrocoolman
24-06-2007, 12:06 AM
Hi Jaison,
60 Hz motor will run on 50 Hz but at reduced speed. The synchronous speed of 60 Hz is 7200/no. of Poles and for 50 Hz is 6000/no. of poles....thus 2 pole motors run at 3600 rpm (less slip) on 60 Hz and 3000 (less slip) rpm on 50 Hz.
Expect about 17% reduction in refrigeration capacity.
As to current draw (and motor protection devices) and compressor motor thermal state you will need to address these issues separately.
Are these compressors single or 3 phase? If 3 phase and capacity and current draw are critical then think about supplying compressors from an Variable Speed Drive.....ths will get round your problem.

Samarjit Sen
24-06-2007, 06:26 AM
All refrigeration manufacturers and other equipment suppliers have both the 60 Hz and 50 Hz and also the different volts. While ordering you have to select as electricity conditions and select the same . In our country we have 50 Hz, 3 pahes 380/400 volts AC supply. We are getting the compressors and the Evaporators from USA and Europe for this application. A 60 Hz being operated at 50 Hz will reduce the speed and the reverse will increase the speed.

suny
24-06-2007, 05:50 PM
All compressor & other electrical manufacturers through out the world manufacture electrical appliances for the electrical supply prevailing in that particular country. Therefore when you order you must specifically state the electrical supply of your country. So they will supply with the correct voltage & cycle. If you use 60 Hz with a supply of 50 Hz, the performance of the compressor will be less and due to less in voltage. It will get heated up than the normal level. During summer in UAE some times the compressor will trip off due to overheating.

Viz, same will apply if you use 50 Hz with a supply of 60 Hz. It will give increase performance due to higher speed and the winding will get heated up. The winding coils will burn after some time. You can not operate for a reasonable period of time. Further please bear in mind that compressors are manufactured to generate certain amount of heat during gas compression. Therefore the extra heating of the compressor is injurious to it. To overcome this problem you could install a electronic speed driver which will give necessary voltage & the cycle for the equipment but this is more expensive than the compressor. So you have to decide to throw or use itů.

The MG Pony
24-06-2007, 06:37 PM
Don't throw em out! Throw em on ebay and recover your investment!

jaison
24-06-2007, 07:20 PM
Hai Electrocoolman,
I am asking about the 220v 50hz , but compressor working in 60 hz, so running ammps became high. I wants to reduce the amps, any capacitor can reduce the amper?. Thanks for your detailed reply, also please think for me about this note. THANKS

Electrocoolman
30-06-2007, 02:07 AM
Hi Jaison,
Sorry for not replying sooner but have been busy working....
So as I understand, you have a 220v 50Hz compressor which you want to run on 60Hz, but when you do, it draws too much current.?

What is the line voltage of your supply?
What is the make and model of the compressor?
What is the actual plate details on the compressor...i.e. is there a voltage range on the plate?

The 50Hz compressor will run faster on 60Hz, thus the system refrigeration capacity will be increased. If the system is a precharged capillary system it could be that the system is overloaded as it will be pumping more refrigerant and thus you might be 'overcharged'.
Have you checked the system pressures? Too low suction and too high on head pressure / condenser only partially available due to excess refrigerant, causing your high compressor current.?

Just a thought....but await further info.
Adrian.

Chillerguy
10-07-2007, 03:26 PM
We have come across this several times. You want to run the 60hz voltage but at 50 hz, correct? The only way we have been able to overcome it is to use a transformer to buck down the voltage to the 50hz rating. Otherwise you will draw to much current and burn up the motor.

frank
10-07-2007, 08:09 PM
We have come across this several times. You want to run the 60hz voltage but at 50 hz, correct? The only way we have been able to overcome it is to use a transformer to buck down the voltage to the 50hz rating. Otherwise you will draw to much current and burn up the motor.
Using a transformer will certainly reduce/increase the voltage but the frequency will stay the same.

To alter the frequency you need an electronic frequency converter

Electrocoolman
11-07-2007, 09:17 AM
Hi Jaison

Have you cured your problem yet? We're all waiting....

Peter_1
11-07-2007, 09:24 PM
The 50Hz compressor will run faster on 60Hz, thus the system refrigeration capacity will be increased. If the system is a precharged capillary system it could be that the system is overloaded as it will be pumping more refrigerant and thus you might be 'overcharged'.
.
If it runs faster like you said, then for a given evaporator it will evaporate lower and evaporating lower is drawing less running current. Agree?
The system will balance to a new point but this isn't that easy to calculate or predict.

theboss
12-07-2007, 01:06 AM
The company my dad works for installed several British made splits units during 80 and early 90's. I forgot the brand name but their indoor unit was quite class and build quality was fantastic. Their compressors were all rated for 50Hz as indicated by their spec plate and been running fine on 60Hz supply in Saudi Arabia. My unit is still functional since purchased new in 80's. Nobody ever faced a complain, incident or damage due to difference of frequency.

There wasn't a 60Hz version from OEM. When my dads employer decided to import them in Saudi, they tested a few units found them working fine and proceeded with bulk imports.

themba
14-08-2007, 12:33 PM
Hai engineers,
How is the after effect if 50 hz compressor work in the 60 hz 220 v suplay, also 60 hz in 50 hz suplay . Thanks.

Does the name plate indicate both frequencies?

SteinarN
16-02-2008, 09:46 AM
The main issue is the motor. The compressor itself can easily be operated at the rpm coresponding with the suplied Hz.

This is how it works:
A motor designed for 220V 50Hz draws some amps and output some power. At 60 Hz the rpm is increased with 20% and the power output also increases with 20% when driving a compressor at the same operating pressures. In order to acheive 20% increase in power output either the voltage or amps have to increase.
The copper wire in the windings in the motor is designed for a maximum amps rate. This amps is stated on the name plate. If this amps is exceeded the windings develop to much heat and the motor can overheat and burn.

When this 50 Hz motor is operated on a 60Hz 220V grid the amps will increase with aproximately 20% and possibly exceed the max amps on the nameplate. If on the other hand the voltage was increased with 20% the amps wouldnt change at all and all would be fine. A 50Hz 220V motor will operate fine on a 60Hz 264V grid!

The heat developed in the motor will increase with aproximately 20% but this shouldnt be to much of a problem for a compressor if the running conditions is resonable.


On the other hand a motor designed for 230V 60Hz but running on a 50 Hz grid should have the voltage decreased with 17%. (50 is 17% of 60)
The corect voltage for a 230V 60Hz motor running on a 50Hz grid is 192v!

If this was the done the amps would be the same as on 60Hz and the power output would be decreased with 17% du to the redused speed. The heat developed in the motor would also decrease with aproximately 17%. And the motor would be quite happy.

On the other hand if the voltage wasnt decreased, lets say still 230V on the 50Hz grid this would cause an considerable increase in the amps even in face of the 17% decrease in power output! As in the first example this could easily led to the amps exceeding the max allowed as stated on the nameplate.

This is a very simplified explanation on the relationship between the voltage and the Hz on AC 3 phase motors. But it should still give the most important informations on the subject.

Abby Normal
25-02-2008, 07:54 PM
I see a lot of 60Hz equipment that gets another reduced rating set for running at 50 Hz. Never seen it the other way around.

kahootshop
19-08-2008, 04:44 PM
Hi ,
I am thinking of importing a used carpigiani batch freezer abd also other refregration stuff from US, as it is very expensive in UK. The apparent problem is is famous 60hz v/s 50hz in uk. Do I need to do major changes with the machine like 50hz compressor change etc or there is some other solution. Can you recommend any refgiration engineer who can do this kind of job. I am in Croydon,london, UK.Please send your reply to my personal email address as well
zammurad@gmail.com

the specs of Carpigiani ice cream bath freezer are

Electrical Requirements

Voltage
Phase
Cycle
Breaker Size
208-230 1/3 60 Hz 50 Amps/40
Running Amps: 39/31 Number of Feeders: 1

kind regards and many thanks

WINJA
20-08-2008, 08:28 AM
We had a real bad time with the solid state cam timers on some Y**k air cooled condensers some years back.

Apparently, the units were made in the USA then shipped over to France where they were rewired to comply with local regulations.

It transpired that the timers were rated for 60hz and couldn't operate properly on the UK electric supply??

Well, thats what Y**k said.

P.S.

Haven't touched ANY Y**k kit since - back up was less than helpful.


I tried to buy one of those cam timers , they wanted almost $1000 for it and they are almost identical to the washtech/starline or older comender comercial dishwasher timer which sold for only $60 and came with a free tool to adjust them, I just repaired the old timer with some knead it putty.

SURESH YADAV
13-12-2008, 10:21 AM
as frequency change the motor r.pm. will change.
as the relation is given below..

rpm= 120*frequency / no of pole.