havertyp
25-11-2008, 12:35 PM
Hello, all
This is a strange one, the problem is on a calibration fluid bath, it is a new one, which this customer 'inherited' from the US, hence the 60Hz spec. It uses a 2 stage cascade, the first stage uses an Embraco (Aspera) hermetic compressor, type J2192GK, running on R507, the second stage uses a Copelametic semi hermetic, type KAMB-007E-CAV-800, running R508b. The Copelametic is spec'd for 208-230V (60Hz) & 200-220V (50Hz). The running current is approx 6.2 - 7A which is slightly above the spec. FLA of 5.6A (the voltage is 238V measured across the run winding). The main problem is the Embraco compressor, it is drawing between 7.7 - 9.0 A, this is way above its specified RLA of 5.4A, it also runs quite hot. The compressor spec is 208 - 230V, 60Hz with RLA = 5.4 & locked rotor A = 40. Is the 50Hz supply the sole cause of this? Again, the voltage across the run winding is 238 V. This site has quite a high supply voltage, maybe the use of a bucking transformer may help.
On a similar 50 Hz spec. appliance, (at same supply voltage), the Copelametic is drawing approx the same current and the Aspera J2212GK hermetic compressor draws approx 3.5 - 4 A, just half what the hermetic on the other machine is using. It is also much cooler to the touch. The specs of this Aspera compressor are: 220 - 240V 50Hz, FLA: 5.3 LRA: 36. Ii notice from the spec sheets that the Aspera on the older machine is rated at 1 HP, whereas the Embraco/Aspera on the new machine is rated at 0.75 HP. Any pointers would be gratefully appreciated as a compressor change would be quite drastic for a brand new machine!
This is a strange one, the problem is on a calibration fluid bath, it is a new one, which this customer 'inherited' from the US, hence the 60Hz spec. It uses a 2 stage cascade, the first stage uses an Embraco (Aspera) hermetic compressor, type J2192GK, running on R507, the second stage uses a Copelametic semi hermetic, type KAMB-007E-CAV-800, running R508b. The Copelametic is spec'd for 208-230V (60Hz) & 200-220V (50Hz). The running current is approx 6.2 - 7A which is slightly above the spec. FLA of 5.6A (the voltage is 238V measured across the run winding). The main problem is the Embraco compressor, it is drawing between 7.7 - 9.0 A, this is way above its specified RLA of 5.4A, it also runs quite hot. The compressor spec is 208 - 230V, 60Hz with RLA = 5.4 & locked rotor A = 40. Is the 50Hz supply the sole cause of this? Again, the voltage across the run winding is 238 V. This site has quite a high supply voltage, maybe the use of a bucking transformer may help.
On a similar 50 Hz spec. appliance, (at same supply voltage), the Copelametic is drawing approx the same current and the Aspera J2212GK hermetic compressor draws approx 3.5 - 4 A, just half what the hermetic on the other machine is using. It is also much cooler to the touch. The specs of this Aspera compressor are: 220 - 240V 50Hz, FLA: 5.3 LRA: 36. Ii notice from the spec sheets that the Aspera on the older machine is rated at 1 HP, whereas the Embraco/Aspera on the new machine is rated at 0.75 HP. Any pointers would be gratefully appreciated as a compressor change would be quite drastic for a brand new machine!