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pakblogger2012
23-08-2014, 05:58 PM
Dear fellow ,I am confused by technical specs of chiller and installed cable and breaker rating.
Following technical specs are written in chiller docs.

Absorbed Power = 86 KW

Nominal operating current = 145 A

Max operating current = 244 A

Now which of above parameter should be used for cable and breaker sizing? .

It is worthy to mention that chiller is water cooled twin screw compression chiller.

I have found that contractor has used 70 mm2 cable and 400 A rating breaker.

Please share your expert views as I suspect that above sizing is not compatible with chiller rating.

install monkey
23-08-2014, 07:26 PM
look at lra - locked rotor ampage, your lenght of cable run, type of cable used, whether its in free air, will determine your cable size, the fuses are designed to protect the cable from melting
see the link
http://www.openelectrical.org/wiki/index.php?title=Cable_Sizing_Calculation

pakblogger2012
23-08-2014, 07:34 PM
look at lra - locked rotor ampage, your lenght of cable run, type of cable used, whether its in free air, will determine your cable size, the fuses are designed to protect the cable from melting
see the link
http://www.openelectrical.org/wiki/index.php?title=Cable_Sizing_Calculation

Can I take maximum operating current as LRA?
The only information I have in this case is mentioned above .
plz help in this case .

install monkey
23-08-2014, 08:27 PM
whats the make/model number of the chiller?, theres no harm in oversizing the cable -apart from the additional cost

pakblogger2012
24-08-2014, 06:45 AM
whats the make/model number of the chiller?, theres no harm in oversizing the cable -apart from the additional cost

Chiller model : Interklima (Greece) WWC-105

install monkey
24-08-2014, 11:00 AM
ive checked the sales info and doesnt state any compressor reference to check lra
best to contact the sales office as if your going to be buying 1 then they should provide you with an installation manual prior to ordering


Contacthttp://interklima.gr/images/icon-note2.png
http://interklima.gr/media/contacts/images/con_address.png70o klm Athens - LamiaHalkidaPO 191 73 34 100 Greece

http://interklima.gr/media/contacts/images/con_tel.png+30 2262085600
http://interklima.gr/media/contacts/images/con_fax.png+30 2262085728


http://www.interklima.gr (http://www.interklima.gr/)

pakblogger2012
24-08-2014, 11:58 AM
Let I put in simple what I intended to ask. (For the time
being put all other things aside, plz )Theoretically which of following parameter is considered for breaker/cable sizing?

Absorbed Power = 86 KW

Nominal operating current = 145 A

Max operating current = 244 A

install monkey
24-08-2014, 12:04 PM
max operating current

Let I put in simple what I intended to ask. (For the time
being put all other things aside, plz )Theoretically which of following parameter is considered for breaker/cable sizing?

Absorbed Power = 86 KW

Nominal operating current = 145 A

Max operating current = 244 A

r.bartlett
24-08-2014, 12:45 PM
Voltage: 400V


Load: 221.7kW / 400A


Length: 20m


Method of Installation: Clipped direct

Cable Size: 150mm˛

pakblogger2012
24-08-2014, 06:17 PM
I need your kind attention to following thread also.

http://www.refrigeration-engineer.com/forums/showthread.php?43614-Types-of-Current-Terms-in-an-Induction-Motor&p=299956#post299956 (http://www.refrigeration-engineer.com/forums/showthread.php?43614-Types-of-Current-Terms-in-an-Induction-Motor&p=299956#post299956)

nike123
24-08-2014, 09:27 PM
Cable is sized according to start method of compressors, allowable voltage drop, cable length, placement, ambient conditions and many more factors influencing proper function of Chiller.
Therefore, it is job for electrical engineer to make calculation and other details for correct cable size choice and installation.

Breaker is sized according to chosen cable and type is chosen according to maximum starting current and duration of start condition.