Dimensions

The fume cupboard shall have the following external dimensions:-

*1000/1200/1500/1800mm (W) x 750mm (D) x 1405 (H)




*Delete as required for fume cupboard size

Chamber

The chamber shall be glazed on all sides with 6mm toughened glass, supported by white P.V.C. extruded sections with minimum section styles for ease of viewing and maximum lighting.  Clear P.V.C. panels or sides will not be acceptable.

Sash

The two sashes shall be of the vertical type, glazed with 6mm armour plate glass and counter balanced by a two concealed weights supported on stainless steel cables running on ball bearing pulleys.  The bottom of each sash shall have a full length aerofoil section and two (2) moulded handles fixed approximately 100mm from the bottom of the sash.  The sash runners and channels shall have seals to ensure they are completely airtight and a minimum opening of 50mm shall remain when the sash is fully lowered.

By-Pass-EXCLUDE IF SYNCROFLOW USED

The cupboard shall be fitted with a concealed by-pass system to assist in lowering the high face velocity at small openings.  With the sash raised the by-pass system shall be completely sealed off to give all the available extraction through the sash opening for maximum safety.  The extraction rate from the fume cupboard should remain constant, irrespective of the position of the sash.

Lighting

The fume cupboard lighting shall be by a fluorescent light mounted in a purpose made G.R.P. moulded cover and shall provide illumination at the work surface through a sealed armour plate glass panel recessed in the roof of the chamber to avoid disturbing the airflow within the fume cupboard. A CLEAR P.V.C. PANEL WILL NOT BE ACCEPTABLE.

Worktop

The worktop is to be Laboratory Grade "Trespa" with rebates for services as required and shall have a front lip to assist in the retention of any accidental spillage.

Services

Service outlets within the fume chamber shall be finished in electrostatically applied epoxy finish colour coded to suit the service.  The remote controls shall be of the Armitage Shanks Marklab range with flow regulating facility and all handles shall be colour coded to the DIN 12920.

Fume Cupboard Electrical and Gas Isolation Equipment

The fume cupboard(s) shall be supplied with a Dynasafe Mk 3 Control System (or approved equal).  This Control System is to be an electronic, programmable P.C.B. module containing 40 x 4 character liquid crystal back lit display (LCD) allowing full status display without abbreviation, and all switches, timers and relays to enable the fume cupboard to comply with the Australian Standards, Nos. 2243.8-1992, 3000-1986 and 2430.3-1991 Appendix 'A'.

The Control System shall also have an RS485 multi drop communication channel which will allow the system to communicate with other computers or building management systems over long distances and in electronically noisy environments.  (Note: RS232 communication channel does not have adequate noise immunity and distance capabilities and is not acceptable.)

The System is to be complete with a special adjustable flow sensor which allows (in the event of an extraction rate failure) the Control System to activate an 75 DB alarm and graphic warning display on the LCD, and will turn off power and gas supplies via a contactor and solenoid valve.

The module shall also incorporate an internal battery back-up supply to ensure alarm activation and graphicindication when the power supply is lost either by circuit failure or power failure;  as required for compliance to AS2243.8 1992.

The Control System shall be complete with pre-purge, and post purge timers, all graphic indication giving status of fan, light, pre-purge, post-purge, power/gas availability, alarm, alarm mute. (It shall also contain controls for spray bar, fume scrubber pump, Syncroflow Sash System and heat sensor to operate when these are installed).

Fitted on the control module shall be an "Fume Cupboard Emergency Isolator" with graphic indication which when activated will isolate power/gas supplies, but will allow the fan to continue running as required by the Australian Standards.

The unit shall also be programmable by the operator to start or stop the fume cupboard at any preset time, to allow automatic out of hours operation.

Syncroflow Energy Saving Sash System (If Syncroflow System is required)

The fume cupboards shall be complete with Syncroflow Sash System to control the fume cupboard extraction fan r.p.m.

The system shall be capable of giving an infinitely variable air volume in relation to the sash position whilst maintaining a capture velocity of not less than 0.5 m/s across the open sash.  When the sash at its minimum opening of 50mm the extraction rate shall be automatically set to give a minimum of five fume cupboard chamber air changes per minute as required for compliance with AS2243.8-1992.  The system must be capable of giving immediate response to any movement of the sash, therefore limit switches will not be acceptable.

The Syncroflow Sash System shall monitor the total extraction volume and activate an audio/visual alarm in the event that the air flow exceeds the equivalent of 1 sash opening.

An auto/boost switch shall be incorporated in the fume cupboard control module.  When the boost switch is activated it should override the automatic mode of the controller and instantly provide maximum air quantity from the extraction fan, irrespective of the position of the sash.  When the auto switch is activated the fume cupboard should immediately return to its normal synchronised mode.

Note:

Pre-set multi speeds operated by switches or motorised damper by-pass system or D.C. motors will not be acceptable.

All wiring to the discrete elements of the controller should be provided and installed by the supplier.

Terminals should be provided within the control unit for connection to an incoming single phase 240 volt supply and 3 phase output for wiring to the 3 phase motor fitted to the extraction fan.  All wiring shall comply with AS3000.

An outlet terminal shall be supplied in the discharge duct which acts as a non-return valve which will seal the exhaust system to ensure no fume re-enters the laboratory when the fume cupboard is idle, and to maintain a minimum discharge velocity of 10 m/s.

Prewiring of Fume Cupboard

The fume cupboard manufacturer shall completely pre-wire the fume cupboard including all lights, G.P.O., solenoids, relays, timers and alarm system.  Terminals shall be provided for site wiring by others for the electrical supply to fume cupboard and for wiring to extraction fan.

Extraction Fan