centration of the diluted feed stream, at the operating recovery, is that the water in the machine at shutdown will have total dissolved solids (TDS) concentrations approximate- ly equal to the machine feed TDS level. The low TDS environment created reduces the potential for membrane element fouling during the down period, extending membrane ele- ment life. The purge operates for a ten (10) minute period. During this period, no per- meate is discharged from the machine and concentrate flows from the machine at the nor- mal operating rate. When the cycle is complete, the RO pump will shut down. When the request to restart is received, the RO will restart and operate as normal. If the restart sig- nal is received during the Purge Cycle, the cycle will terminate and the RO will return to normal operating mode.
Since this feature is designed to provide a low TDS environment during extended shut- down periods, the purge sequence will not activate for any
Level control of a permeate storage tank is GE Osmonics’ standard external control device which activates the purge shutdown. Any other remote device(s) can be used where per- meate purge is desired prior to RO shutdown. Examples include: remote ON/OFF, post- treatment lockout, etc.
WARNING: DO NOT CONFIGURE PRETREATMENT DEVICES FOR
To establish the control loop for
WARNING: BEFORE OBTAINING ACCESS TO TERMINALS, ALL SUPPLY CIRCUITS MUST BE DISCONNECTED.
STEPS
1.Establish that the remote device(s) has dry contacts available to provide the shut- down signal to the RO.
2.With power removed from the control enclosure, open enclosure.
3.Wire from the 24VDC source terminal #515 to the first remote device. Wire all additional devices in series with the first. Wire from the last remote device to ter- minal #1007.
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