Shutdown; Power Or Purge Loss Shutdown - Thermo Scientific SOLA II Flare User Manual

Shutdown

Power or Purge Loss
Shutdown
Thermo Scientific
The X-Purge unit automatically removes power from the analyzer system if the
purge pressure becomes less than 0.3 inch of water (0.75 mbar) in any
monitored zone or if enclosure exhaust airflow drops too low. It also
automatically removes power from the analyzer if the instrument air pressure at
the X-Purge regulator is lower than about 10 psig. To manually remove power
from the system, perform the following steps.
1. Perform all shutdown steps listed in the shutdown procedure in the
instrument user's guide up to the point where power is turned off to the
system.
2. Remove power to the X-Purge system.
3. Complete the remaining shutdown steps listed in the applicable
shutdown procedure in the instrument user's guide.
If ac power or purge pressure is lost, the X-Purge unit shuts off power to the
analyzer system. When the power or purge pressure is restored, the X-Purge
begins the purge timer. After the required purge time is achieved, the X-Purge
unit applies power to the analyzer system.
The X-Purge controller interrupts the incoming analyzer electrical power.
Power to 4–20 mA outputs is interrupted upon loss of purge or power, as the
analyzer powers these outputs. The device receiving discrete and/or Modbus
signals from the analyzer may apply power. Consequently, the purged analyzer
enclosure could contain powered wiring even when power to the analyzer is
interrupted. To ensure that the purged analyzer enclosure contains only non-
incendiary power upon interruption of main analyzer power, you may elect to
implement one of the following:
Install the appropriate Intrinsically Safe (IS) barriers on Modbus and/or
•
discrete signals.
Utilize the X-Purge's alarm contacts to drive interposing relays
•
configured such that the Modbus and/or discrete signal wiring
continuity is broken upon loss of main analyzer power.
Appendix F
The X-Purge System
SOLA II Flare User Manual F-7