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Data sheet: Pre-Start Ventilation System

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Data sheet: Pre-Start Ventilation System


Pre-Start Ventilation (PV) is recommended for safe starting of high voltage Ex e and Ex n motors in hazardous areas, where the overall risk assessment (under 60079-7 and 60079-15 respectively) calls for “Special measures”.

The Expo Pre-Start Ventilation System enables users to readily demonstrate compliance with the above equipment standards, and greatly improves safety by eliminating any potentially flammable atmosphere from the machine enclosure prior to start up.


The PV System has two components; the Control Unit (CU) and the Outlet Valve (OV). The CU controls flow into the motor enclosure, with pneumatic logic operating the OV based on flow and time. The OV has two valves; one allows normal ventilation flow and the second provides machine overpressure relief.

In operation, the system provides local indication of ventilation condition and progress, plus volt-free contacts for external indication (see Technical Specification).


  • Three system sizes to cover wide range of flow rates and machine types.
  • Local and Remote Start options for easy incorporation in control schemes.
  • Fully third party approved for Zone 1 application
  • Continuous Ventilation (CV) Option to permit immediate motor re-start after start-up trip.

Explosion Protection

Hazardous Area Classification

ATEX & IECEx certified for use with Electrical Rotating

Machines of types:

Ex e (Zone 1) & Ex n (Zone 2)

Sira 13ATEX1083X IECEx SIR13.0030X

Suitable to protect Class I Div 2 Electrical Rotating


Ambient temperature

-2oo c to +60°C (-4°F to +140°F)

-50°C to +60°C (-4°F to +140°F) Low Temperature Option

Technical specification & Options


‘Ventilation in Progress’ (Off= Black, In Progress = Flashing LEOs)

‘Ventilation Complete’ (Off= Red, Complete= Green)


/PA –     Ex d switches (250Vac 4A) via

Ex e terminals in Ex e IP65 enclosure.


/IS –      Volt free contact closures, suitable

for connection into intrinsically safe or non-incendive          circuits (external protection by others). Blue terminals         in Ex e IP65 junction box.
Terminals accept 0.5 to 2.5mm2·

/PO       Pneumatic Outputs, 4barg signals available via

1/8″ NPT (F) bulkhead fittings.


CV        Continuous Ventilation

System continues ventilating after timing has elapsed,        and permits immediate machine re-start.

Technical Data

Air Supply Pressure

4 to 10 barg

(60 to 150 psig)

Outlet Valve Lift off Pressure

20 to 50 mbarg

(8″ to 20.1″ wg)

Outlet Valve Housing

316 stainless steel