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ML550 | v6

Page

12

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]

Unless a supply shut-off valve has been fitted to the MiniPurge

® 

system, an external shut-off valve with 

the same, or larger, thread size as the Control Unit inlet fitting should be fitted by the installer to prevent any 
restriction of purge flow.

The purge air from the MiniPurge

®

 Control Unit should be piped within the pressurized enclosure to ensure 

purging of potential dead air spots.

The purge system is fitted with an internal regulator factory set to 3 bar feeding the logic.

Pipe Work

If the MiniPurge

®

 is not connected directly to the pressurized enclosure, pipe work and fittings used to connect 

the Control Unit to the pressurized enclosure should be either metallic or appropriate to the environment into 
which the system is installed. No valve may be fitted in any signal pipe connecting the Control Unit to the 
pressurized enclosure. This pipe work must be fitted in accordance with local codes of practice where relevant.

Multiple Enclosures

This system is suitable for the purge and pressurization of the primary pressurized enclosure and its associated 
terminal boxes.

Provision and Installation of Alarm Devices

When the pressure inside the pressurized enclosure is above the minimum, the Minimum Pressure Sensor re-
turns a positive (

pressurized

) signal causing the alarm indicator on the control unit to change from 

red

 to 

green

.

When the pressure falls below the minimum permissible the positive (

pressurized

) signal is removed. This ab-

sence of signal indicates a 

low pressure alarm

 condition and causes the alarm indicator on the control unit to 

go from 

green

 to 

red

.

There are volt free (dry) contacts available within the terminal box for remote usage.

The user must make use of this alarm facility in accordance with the local code of practice for Action on Pressure 
or Flow Failure. Most codes include the following recommendations:

Zone 1 / Division 1 Installations:

 Alarm and Automatic Trip of Power.

Zone 2 / Division 2 Installations:

 Alarm Only on pressure or flow failure with power being removed manu-

ally.

Power Supplies and their Isolation

All power entering the pressurized enclosure should have a means of isolation. This requirement also applies to 
any external power sources that are connected to the equipment such as volt-free (dry) contacts within the 
pressurized enclosure. This is commonly achieved using the Power Interlock Switch.

Power Interlock Switch

This switch is a Double Pole Normally Open, double-break switch: it provides two independent contacts that 
should be connected in series and used to isolate the power. This can be achieved using switchgear or other 
suitable switching device. These contacts are terminated and accessible to the user in the terminal box.

It is the responsibility of the user to ensure that the switch is only operated within appropriate technical limits.

The switch must be replaced after any short circuit that occurs within the main circuit; the switch is a piece of 
encapsulated equipment and as such it is not possible to check the state of the contacts. Technical modifications 
to the switch are not permitted.

Prior to commissioning, check that the terminal box is clean, the connections have been made properly, the 
cables laid correctly and all screws in the terminals are secure.

Summary of Contents for MiniPurge D825/ET

Page 1: ...that the installer and user of the Expo system follow these instructions Please refer to the standard for principles and definition These instructions apply only to the pressurizing system it is the...

Page 2: ......

Page 3: ...sionproof Terminal Box 10 Section 6 Installation of the System 11 Relief Valve Unit 11 Air Supply Quality 11 Pipe Work 12 Multiple Enclosures 12 Provision and Installation of Alarm Devices 12 Power Su...

Page 4: ...T100 C Db Tamb 20 C to 55 C T V INMETRO Certificate T V 12 1462X Ex pxb ia IIC T5 Gb Ex pxb ia IIIC T100 C Db Tamb 20 C to 55 C FM Certificate FM 1X8A4 AE USA Canada Class I Div 1 Groups A B C D Type...

Page 5: ...urge supply and outlet to pressurized enclosure 1 NPT female Minimum supply line 25 mm 1 ID tube Reference points signals 1 8 NPT female Visual Indicators Alarm Red Pressurized Green System Purging 4...

Page 6: ...ral spark arrestor Default Setting 99 minutes Weight 27 kg 60lb Type RLV104 ss FS Bore Purge Outlet Valve 104 mm Relief Valve 75 mm Relief Valve Lift Off Pressure Minimum 20 mbarg Maximum 50 mbarg Def...

Page 7: ...stricted air supply inadequate supply pipe work or drop in air supply pres sure during the purge process Operation of the System Once the system is installed correctly turn on the air supply Refer to...

Page 8: ...quired purge time Note The recorded purge time must never be less than the required purge time The system is now operating correctly in leakage compensation mode If the system has not performed as exp...

Page 9: ...ning switching devices may be limited in their gas group The certification documentation supplied with any such devices must be checked to ensure their suitability This system is primarily designed fo...

Page 10: ...ve entered the enclosure before pressurization Purging is the process of removal contaminated air and replacement with air or inert gas known to be free from flammable gas The duration of this purge p...

Page 11: ...ensor monitors flow through the Purge Outlet Valve At correct purge flow rates above the minimum specified for purging the sensor sends a signal that activates the purge timer This sensor is factory c...

Page 12: ...tivated by the signal of the Purge Complete Valve The pneumatic output for this function is connected to a switch within the explosionproof terminal box This activation can be used to turn on the elec...

Page 13: ...ief Valve Unit When the system changes to leakage compensation mode the Purge Outlet Valve is closed and the enclosure sealed The Relief Valve Unit has an in built relief valve This is sized to ensure...

Page 14: ...any way Air Supply Quality The MiniPurge system should be connected to a protective gas supply which is suitable for purging and pressurization The supply pipe connection to the MiniPurge must be app...

Page 15: ...e pressurized signal is removed This ab sence of signal indicates a low pressure alarm condition and causes the alarm indicator on the control unit to go from green to red There are volt free dry cont...

Page 16: ...power must be controlled by the MiniPurge system using the power interlock signal No switches are permitted between the power switch and the MiniPurge system other than an authorized manual override c...

Page 17: ...minimum pressure sensing pipe was removed Open the Purge Flow Restrictor Valve very slowly until the Pressure Relief Valve opens Check the opening pressure is within calibration limits This test can...

Page 18: ...check readings on manometer as system will automatically re purge when it reaches minimum pressure 20 While the system re purges return the CLAPS Regulator to the initial setting 21 If minimum pressu...

Page 19: ...n There are no unauthorised modifications The air supply is uncontaminated The interlocks and alarms function correctly Approval labels are legible and undamaged Adequate spares are carried The action...

Page 20: ...sitive and it is recommended that a 1 4 turn maximum adjustments are applied between tests Re calibration of the Pressure Sensors The brass nozzle on the sensor is sealed into position using Loctite t...

Page 21: ...esigned for ease of fault finding and many of the components fitted are plug in or chassis mounted Check components by substitution only after establishing that such action is necessary Before carryin...

Page 22: ...pressure drop in the supply pipe Static pressure of 5 barg must be maintained during purge Check air supply pressure at the inlet to the control unit Ensure that the supply pipe bore is suitable for...

Page 23: ...S0030 478 Intermediate pressure sensor must be factory set to the value as stated on the Customer Test and Inspection Sheet S0030 588 CLAPS Sensor must be factory set to the value as stated on the Cus...

Page 24: ...system merely tops up for any enclosure leakage The system provides an initial high flow of purging air that leaves the PE through the Relief Valve After the initial purging has been completed the Co...

Page 25: ...one PE can be protected by a single system If PEs are connected and purged in series e g Daisy Chained the Outlet Orifice must be fitted on the last enclosure with the Purge Inlet to the first enclosu...

Page 26: ...ally by the user by the use of local isolating switch 1 4 2 In accordance with NFPA 496 Expo Mini X Purge systems can have the Action on Pressure Failure normally Alarm and Trip adjusted by the user t...

Page 27: ...ation do not confuse this flow rate with that caused by excessive setting of the LCV Close the LCV slowly observing the manometer or gauge see item 2 1 3 above The PE pressure will start to fall as th...

Page 28: ...quantity The LCV is too far open and the air flow is holding the RLV open continuously Note Some CFHP systems have a deliberate but modest Continuous air flow through the RLV in normal operation do n...

Page 29: ...in the air supply For this reason a dust and water filter should always be fitted But debris can enter from other sources and it is vital therefore that the procedures described in Section 2 is carrie...

Page 30: ...d Is the pipe to the Power Switch airtight The signal to the Power Switch bulkhead has a restrictor that limits the permissible leakage from the pipe e Note the timer setting Reset the timer to the m...

Page 31: ...SIRA 01ATEX1295X IECEx Certificate IECEx SIR07 0027X INMETRO T V Certificate T V 12 1462X FM Certificate USA Canada 1X8A4 AE USA Canda MIU d Terminal Box ATEX Certificate SIRA 02ATEX1129 IECEx Certif...

Page 32: ...CH 120V 6A SPNO 26 31 30 29 28 27 24 25 23 22 21 20 19 18 PURGE COMPLETE VALVE I S BATTERY PACK TIMER VALVE MAIN AIR SUPPLY FILTER REGULATOR GAUGE MAIN AIR SUPPLY GAUGE LOGIC AIR SUPPLY LOGIC AIR SUPP...

Page 33: ...VE INDICATOR ALARM PRESSURIZED RED ALARM GREEN PRESSURIZED D P LO D P HI PURGE VALVE TO OPEN SIGNAL 1 CONTACTS 120V 6A 250V 3A CONTACTS 120V 6A 250V 3A CONTACTS 120V 1A JUNCTION BOX OR GATE TIMER VALV...

Page 34: ...EF VALVE PURGE OULET VALVE OPEN SIGNAL TO RELIEF VALVE AIR OUTLET FROM RELIEF VALVE MOTOR TERMINAL BOX AIR INLET ALARM PRESSURIZED CONTACTS INTERMEDIATE PRESSURE CONTACTS MOTOR INTERLOCK CONTACTS PURG...

Page 35: ...way against our interests NO DEC PLACE 0 5 1 DEC PLACE 0 2 2 DEC PLACE 0 1 2 4 7 3 6 8 WIRE SIZE FOR CONTACTOR RELAY AND TERMINALS 2 5mm 14 AWG MAX 5 1 1 2 3 DESCRIPTION Ex d EXPLOSION PROOF ALUMINIU...

Page 36: ...e i p o c e b o t t o n e r a y e h T t s e u q e r n o p u e l b a n r u t e r e r a d n a s t s e r e t n i r u o t s n i a g a y a w y n a n i d e s u e b o t y e h t e r a r e h t i e n d e t i m...

Page 37: ...ormal operation Key to functions Minimum Pressure sensor turns on Purge Complete signal to electrical Power Switch Automatic operation by the system No PRESSURIZED INDICATOR Purge Outlet flow above th...

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Page 39: ...This Page Intentionally Left Blank...

Page 40: ...Technologies UK Expo Technologies Ltd Unit 2 The Summit Hanworth Road Sunbury On Thames TW16 5DB UK T 44 20 8398 8011 F 44 20 8398 8014 E sales expoworldwide com Expo Technologies China Qingdao Expo...

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