ML548_ES | v3
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Expo Technologies UK
T: +44 (0) 20 8398 8011
E: [email protected]
Expo Technologies US
T: +1 (440) 247 5314
E:[email protected]
Expo Technologies China
T: +86 532 8906 9858
E: [email protected]
Section 7: Commissioning
Commissioning the System
Note: The steps 12 and 16 to 22 represent detailed commissioning tests
The following equipment is needed for this process:
• Continuity meter
• Gauge manometer (0 to 200 mbarg)
• Differential manometer
• 2 off 4mm plugs
If, after commissioning, the system does not perform as expected, refer to the Fault Finding Section.
Follow the steps as outlined:
1. Connect power to the heater via terminals 1 (Live) 4 (Neutral) and where required 3(Earth) of the Ex d
junction box and check continuity across terminals. An earth terminal is also provided within the junction
box if required. Purging is permissible only when an internal temperature of -10°C or greater has been
validated by purge environment RTD sensor.
2. Check that the cable and pipe are securely connected to EPPS. Check that the exhaust on the EPPS is not
obstructed.
3. Check all connections and that the Relief Valve Unit is fitted correctly with an unobstructed path to the
purge exhaust.
4. Set CLAPS regulator & Purge Flow Regulator to 0.
5. Fully open external supply shut-off valve where fitted.
6. Check that the internal logic pressure gauge reads 2.5 barg / 36 psi / 250 kPag.
7. Check that the pressure gauge on main air supply reads 4.2 barg / 61 psi / 420 kPag.
8. Check that the Pressure Relief Valve is correctly set by isolating the High-Pressure Sensor and Purge
Outlet Valve. To do this locate High-Pressure/Open Purge Outlet Signal bulkhead. Follow nylon tube back to
the y-piece connector. Remove tube & plug.
• Remove red plug from the top of the Minimum Pressure Sensor and connect a gauge manometer.
• Raise the internal pressure by turning the CLAPS regulator clockwise till the Low-Pressure Alarm
Indicator turns green. This activates the Purge Flow Regulator.
• Slowly open the Purge Flow Regulator until the Pressure Relief Valve opens. This is the set point.
• This test can be carried out several times to ensure repeatability and compliance.
Refer to the Maintenance of the System section if the Relief Valve needs recalibrating.
9. Reset CLAPS regulator & Purge Flow Regulator to 0.
10.De-isolate the High-Pressure Sensor and Purge Outlet Valve.
11.Connect a differential manometer to the test points on the flow sensor.
12.To check sensor calibration
• Raise the internal pressure by turning the CLAPS regulator clockwise until the Low-Pressure Alarm
Indicator turns green. This will activate the Purge Flow regulator & Purge Outlet Valve. The pressure will
fluctuate as the Purge Outlet Valve opens/closes. This is normal.
• Gradually open the Purge Flow Regulator until System Purging Indicator flashes yellow.
• Gradually close Purge Flow Regulator Valve until the purging indicator stops flashing yellow.
• Take a reading from pressure gauge.
13.To set the purge flow rate:
