Purge & Pressurization systems for large Ex p electric motors & generator
Features
● Global certification
● Purge flow rate up to 6,000 Nl/min
● Use CLAPS technology to ensure internal pressure of the equipment
● Stainless steel shell structure
● Temperature range -20°C to +55°C
● System model: D771 (for intrinsically safe circuits)
The D771 purge and pressurization system delivers purge flowrates up to 6,000 Nl/min and is ideal for medium to large sized Ex p electrical machines.
The system comprises the Control Unit (CU) and the Relief Valve (RLV). The Control Unit contains the pneumatic logic to monitor and control air flow, pressure and purge timing, and provides the system outputs. The RLV measures purge flow at the outlet and provides over-pressure protection for the machine.
The D771 incorporates Expo’s Closed Loop Automatic Pressurization System (CLAPS). This allows the system to detect a rise or fall of the enclosure’s internal pressure and adjust the leakage compensation rate accordingly.
Pressure variations are more likely during sudden start-up of large rotating electrical machines but can also be caused by changes in running temperature. This system has been specifically designed to maintain a stable internal pressure within the motor enclosure.
There are system variants to cover alternative alarm output connections - see Specifications & Downloads for further details.
| Air Inlet | Instrument quality air，5-16 barg |
| Purge flow rate | 2,000、3,000、4,000、5,000、6,000 NI/min |
| Leakage compensation capacity | Up to 1,500 NI/min |
| Temperature range | -20°C to +55°C |
| Purge timer | 1-99min |
| Timer power source | IS (Intrinsically Safe) Battery or Electro-Pneumatic Power Supply (EPPS) |
| Signal outputs | Function: Power interlock, low pressure alarm, intermediate pressure alarm, purge in progress (optional) |
| Certifications* | IECEx、ATEX、INMETRO、KOSHA、EAC、FM、cULus |
*Not all certifications apply to all system variants. Check the specific Operating and Maintenance Manual for details.
