Entron EN1000 series

Page 24
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SOLID STATE MANUFACTURER'S COOLING RECOMMENDATIONS
600 AMP SCR Solid State Contactor
1200 AMP SCR Solid State Contactor
1800/2200 AMP SCR Solid State Contactor
1 GPM at 104(F (40(C) maximum inlet temperature.
TUBE MANUFACTURER'S COOLING RECOMMENDATIONS
This chart shows typical cooling requirements at 500VAC operation in GPM.
Maximum water temperature 50(C (122(F)
IGNITRON TUBE SIZE
WATER INLET
TEMPERATURE
B
C
C½
D
15(C (59(F)
1/4
3/8
1
1-1/2
30(C (86(F)
1/2
1/2
1-1/2
2
40(C (104(F)
1-1/2
1-1/4
1-1/2
3
Be sure power to an electronic contactor is turned off when water is turned off.
With a voltage applied, most water will ionize and begin to conduct current between tubes.
This current is sufficient to heat the water past the boiling point, creating steam and possibly
causing the rubber hose to burst. The water spraying over the high voltage circuit can cause
considerable damage to the contactor and, most likely, the control circuitry as well. Never
use metallic or other conductive tubing to plumb a water cooled resistance welding
contactor. Heater hose has a very high carbon content and should not be used for contactor
plumbing. A low carbon, reinforced hose (such as the hose originally supplied with the
unit), no less than 18" long, must be used to connect the tubes to each other and to the
bulkhead fitting on the inside wall of the cabinet, see plumbing instructions on wiring
diagram.
The 600 Ampere water cooled contactor in the EN1000-"S" Cabinet is electrically isolated
from the electrical circuit within the contactor. All water connections are made external to
the control cabinet. No minimum length of water hose is required for electrical isolation of
the contactor. It is still recommended to turn power off when the control is not in use.
For all water cooled contactors, be sure water is turned ON before placing welder in
operation. An open drain is recommended for best operation. If a closed return system is
used, be sure return line is properly sized so that back pressure will not reduce water flow
below recommendations. A sight flow indicator is recommended.
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