SPECIAL REVERSE HORIZONTAL FLOW ENCLOSURE OPERATING AND MAINTENANCE MANUAL Issue No: 1
Certificate No: 0954499 CE Marking certifies that this equipment conforms to the following EEC directives: - Low Voltage Equipment - 72/23/EEC & 93/68 EEC Electromagnetic Compatibility - 89/336/EEC
C O N T EN T S DESCRIPTION...5 INSTALLATION AND OPERATION...6 OPERATION...6 FILTERS...7-8 PRE-FILTER (PART N :- GS 132039/pre. QTY 1)...7 MAIN FILTER (PART N :- 132039/HEPA. QTY 1)...8 AIRFLOW...9 AIRFLOW MONITORING...9 MINIHELIC GAUGE...9 SERVICING...10 MAINTENANCE...11 CALIBRATION...12 ACCESS...12 CALIBRATION PROCEDURE...13 FAULT FINDING... 14 SYSTEM SCHEMATIC 15-16 ELECTRICAL WIRING DIAGRAM...17 CONTACT INFORMATION.18
DESCRIPTION REVERSE HORIZONTAL LAMINAR FLOW CABINET The special reverse laminar flow cabinet is designed to provide operator protection only, while weighing out and using hazardous powders including powdered culture media, which may be cytotoxic or mutagenic. The unit has a disposable pre filter (filtrate EU4 grade 95% efficiency at 0.5 microns, housed in a removable 316-grade sandwich frame grille arrangement (see technical illustration Fig.1) to capture the majority of the powder, and primary HEPA filter in the rear of the unit (EU7 Grade 99.998% efficiency at 0.3 Microns, as an absolute filter for any remaining powders. There are twin cable access ports, one on the right hand side panel, and one on the left hand side panel to permit cable entry into the cabinet. The unit is bench mounted. The cabinet is manufactured in epoxy Zintec mild steel with a 316-grade stainless steel work surface, and pre-filter housing grille. To provide a vibration free work surface, a heavy granite weighing block on anti-vibration feet is fitted to the work surface and is removable for cleaning. Air is drawn over the work surface, and to the rear of the unit in a reverse horizontal laminar flow, away from the operator, through the panel pre-filter and HEPA filter mounted in the rear of the cabinet, by the fans positioned in the head of the cabinet. The clean air is exhausted at the top of the cabinet, and re-circulated back into the room as HEPA filtered sterile and dust free air. No external exhaust is required. The filter seals are under negative pressure to eliminate leakage past the seals into the rear plenum and thus ensure the quality of the air returned to the work environment. Airflow at 100mm off filter face is between 0.43 to 0.55 m/sec. The unit is capable of passing a KI discuss test for containment. 5
INSTALLATION AND OPERATION The unit will be supplied ready for final assembly and commissioning on site by Puricore engineers. It is fitted with a correctly fused mains 3 pin plug fitted. IMPORTANT: THIS APPLIANCE MUST BE EARTHED OPERATION The cabinet is fitted with the following controls and instrumentation: a) b) c) d) e) Mains on/off rocker switch Hours running meter Lighting switch on/off Fan high/low speed switch Fan speed adjusting potentiometers (Calibration use only) f) Minihelic gauge - HEPA filter status indicator g) Airflow indicator, with low airflow alarm system The unit is started by switching on the mains rocker switch and the light switch. The fan switch should be on low speed when the HEPA filter is new. The work surface is fixed with the exception of the granite antivibration section which is removable for cleaning, and any powders that have dropped around it can be cleaned up using a damp cloth and suitable cleaning solution. The unit should be running during this process so that there is operator protection from any powder disturbed during this procedure, the powders being contained within the work area by the airflow in the unit. 6
FILTERS PRE-FILTER (PART N :- GS 132039/pre. QTY 1) Size: 880mm x 650mm x 20mm each The pre-filter is positioned at the rear of the unit in front of the HEPA filter. See fig.1 illustration. The filter is sandwiched between two stainless steel hinged grille panels, retained at the top by thumb screws to enable quick release of the filter retaining grille for maintenance. The pre-filters will remove 95% of the particulate matter to 0.5 microns, in the air stream and must be replaced when the low airflow alarm light is illuminated, or at regular maintenance intervals, i.e. weekly depending upon powder loading. To change the pre-filter: 1) Undo the thumb screws retaining the hinged grille panel. 2) Hinge the grille panel forwards from the top to rest on the work surface, see fig.1 illustration. 3) With the unit running, remove the used pre-filter from the rear part of the sandwich section, towards the front of the unit. Carefully remove the dirty pre-filter and bag ready for disposal 4) Place new pre-filter in position, ensuring that it lies flat on the rear grille section of the filter housing and covers to the edges. Replace pre-filter frame, and then hinge the grille panel back up and retain in place with the thumb screws. NOTE: 1) 2) This should be done with the unit running to provide operator protection during this procedure. Once the grille panel is hinged down, the face of the prefilter can be sprayed with a lacquer (hair spray) before being moved as this reduces the amount of dust that can fall off the pre-filter face, if necessary as this depends upon the adherence of the powder to the pre-filter material initially. 7
FILTERS contd. PRIMARY FILTER (PART N :- GS 132039/HEPA. QTY 1) Size: 880mm x 675mm x 66mm each The primary HEPA filter is mounted from the front of the cabinet behind the pre-filter and the seals are under negative pressure to avoid leakage into the cabinet. The filter is 99.997% efficient against 0.3 micron particles. The main filter will require changing when the airflow alarm is illuminated and changing the pre-filter does not restore the airflow. The main filter will normally be changed by an engineer, as the filter integrity should be checked by a D.O.P. test before the cabinet is used. 1. To access the primary HEPA filter, first remove the pre-filter as described above 2. Then remove the rear pre-filter grille assembly be undoing the retaining screws in all four corners, the entire pre-filter grille sandwich assembly can then be removed from the cabinet. This may also be useful if intensive cleaning of the pre-filter grille housing assembly is required. 3. Once removed the primary HEPA filter housing retaining clamp can be accessed, this again is retained by four bolts, one in each corner, the bolts can be undone, and the filter clamp removed, then the primary HEPA can be removed. 4. Re-fit with new replacement HEPA filter ensuring all seals sit into their respective housings and no seals are trapped or damaged. 5. Test the cabinet with DOP to prove filter and seal integrity, this is a safety aspect and must be done following main HEPA filter replacement. DOP testing must be carried out by a suitably qualified engineer. NOTE: the cabinet should be switched off during this procedure to ensure that no powders that become dislodged are ejected by the fans into the room. 8
AIRFLOW The airflow is set by pulling out the plastic inserts on the left hand side of the control panel. The fan speed can now be adjusted to the desired level. As this cabinet is for powder weighing, the high speed has been set to average 0.65-0.55 m/sec and low airspeed to 0.43-0.55m/sec. Note: This will normally be carried out by an engineer during commissioning or at service. The unit is normally run on the low speed, with the high speed switch being used to enhance the airflow and extend the filter life as the filter becomes blocked i.e. where the low airflow alarm shows on the low speed, switch the unit to high speed fan. The low airflow alarm should turn off. When the low airflow alarm is displayed on high airflow speed then the HEPA filter requires changing. AIRFLOW MONITORING The airflow should be checked at 6 monthly intervals with a rotary vane anemometer, at a distance of about 100mm from the filter face. High fan speed should be selected when the airflow on fan speed one falls below 0.35m/s and the alarm is displayed. MINIHELIC GAUGE This will indicate when the filter is approaching the end of its life. The normal maximum pressure will be about 32mm when the filter requires changing. 9
SERVICING An annual service is recommended and will cover the following points; a) b) c) d) e) f) Airflow check and reset if necessary Filter condition check by D.O.P Inspection of electrical components, lighting, cables etc Cleaning and checking the condition of the glazing Examination of services if fitted. The gas supply line must be checked carefully for leaks and damage if fitted. Issuing of a test report complete with an airflow certificate. 10
MAINTENANCE WARNING - Removal of the panel will expose electrical contacts. Disconnect electrical supply before opening. i) ii) iii) iv) FILTERS - The pre-filter requires replacement when alarm light is illuminated. Or when visual inspection clearly shows excessive debris on the filter (this is clearly visible through the grille mesh that covers the filter. See section on filters. AIRFLOW - The airflow will require checking at routine intervals. See section on Airflow. LIGHTING - The lighting is accessible from inside the cabinet. The diffuser panel under the lights can be removed to give access to the electrical components. The units are complete with starters and chokes. AIRFLOW ALARMS The unit is normally operated using fan speed 1 and as the pre-filter blocks the red neon will start to illuminate. Switch the fan speed to setting 2 to prolong the filter life, when the neon illuminates again change the pre-filter, if the neon is still illuminated change the HEPA filter. Once both the pre-filter and HEPA filters have been changed set the fan speed back to speed setting 1. 11
CALIBRATION The cabinet is fitted with two pressure sensors to detect the condition of filters. ACCESS The control panel has access plugs and the adjustments are inside. Pressure switch A - lower: This is for the main HEPA filter condition and operates the red indicator lamp on the mimic display. Pressure switch B - upper: This is for the pre-filter and operates the red lamp on the pre-filter mimic display. The pressure switches are at low voltage and have a central adjusting cross head screw. 12
CALIBRATION PROCEDURE Note: Unit requires the fitting of a new pre-filter before being recalibrated. 1 2 3 4 5 6 7 8 9 10 11 Pull out access plugs. Switch cabinet on and allow fan to reach normal operating temperature by running for ten minutes at fan speed setting 1. Adjust fan speed control to give an outflow average approximately 0.43-0.55 m/sec on fan speed (1) setting. Block approximately half of the inlet grill with plastic sheet (or paper etc). The upper pressure switch is now adjusted to just come on Screw anti-clockwise to illuminate Screw clockwise to switch off Remove plastic sheet Decrease fan speed to give an airflow of 0.36m/sec Adjust lower switch so main filter just comes on Screw anti-clockwise illuminate Screw clockwise to switch off Return fan speed to normal running speed Check airflow is still 0.43-0.55m/sec average on fan speed (I). Switch to fan speed (II) and adjust fan speed to >0.55m/s (0.6-0.65m/sec) on fan speed (II) setting. Replace access plugs 13
FAULT FINDING WARNING! 240V - ONLY QUALIFIED PERSONNEL TO CHECK ELECTRICAL CIRCUIT AND COMPONENTS Unit will not switch on fan or lighting circuit Check: a: Main fuse in plug and that electricity is turned on at the mains switch b: The fuse in the head unit c: Condition of mains inlet cable Lighting fault on one or both lights Check: a: Starter switches inside the cabinet (see section on maintenance) b: Replace fluorescent tube inside the head unit Fan off but lights on Check: a: b: SWITCH OFF - allow unit to cool (if warm) and restart. If fan now starts then the thermal overload in the fan has been tripped Failure of fan or fan capacitor - contact MAJIC SYSTEMS for replacement items 14
RV-HLF-9 SYSTEM SCHEMATIC 15
RV-HLF-9 Fig.1 Showing pre-filter grille sandwich removed and main HEPA filter located behind, detailing main HEPA empty housing plenum. Showing pre-filter grille in drop down position, rear pre filter grille in place. 16
ELECTRICAL SCHEMATIC