Medusa

Medusa is the ambient monitoring system that allows to keep constantly in the safety the vacuum and charging machine within the working area storage area and the refrigerant pressurization area

Medusa can be configured according to the customer specific installation :

• Built in agreement to the European Machinery Directive, CE marked, CE Safety standards for potential dangerous areas
• Basic version suggested with three ambient sensors
• Microprocessor controller
• User interface with alarm lights, display and TOUCH keyboard
• Provided with integrated Acoustic Alarm
• Provided with UPS ( Uninterruptible Power Supply )

Medusa supply and control the EOLO fan rate ventilation by means of a proper Power Electric cabinet. The Power rate can be configured according to the customer layout.
Medusa standard version is provided with catalytic sensors that include (optionally) a sensitivity calibration device to check their performances according to the European Machine Directive.

Necessary devices for Medusa

• Fire alarm box
• Gas alarm indicators column (up to three)
• Fan/door alarm indicators column (up to three)
• Spring + microswitch for charging room door
• Pneumatic, hand and safety valves group + 0,7 l accumulator
• Pneumatic, hand and safety valves group + refrigerant filter
• 30/40 bar safety valve
• EOLO multi speed fan up to 4000 m3/h (400 V–50 Hz–3ph+N+earth)

Main using applications
Medusa advise operators and initiate additional ventilation, when the concentration of Isobutane/Propane reaches 15% of the Lower Flammability. The system provides to cut the power supply to the vacuum and charging unit, putting it in a safety position, where the concentration exceeds 30% of the Lower Flammability. At this point is also given the Alarm because the operators to leave the working area and activate all systems of fire prevention.

• Calibration kit for HC Sensors
• IR environment sensors

Medusa provides to give the Vacuum and Charging unit power supply electrical permission and the relevant Refrigerant Transfer pumps connected to the delivery line.
The electrical permission is real time determined according to the continuous monitoring of the refrigerant concentration detected from the sensors and a ventilation level detected from relevant differential pressure switches installed on the charging area ventilation circuit.

Medusa provides to alert operators and supplies additional ventilation, when the gas concentration reaches 15% of the Lower Flammability. The system will cut power to the vacuum system and charge, putting it in a stand-by safety, if the concentration exceeds 30% of the Lower Flammability. At this point is also given the warning sound on remote (optional) light columns to advise the operators to leave the working area and all fire prevention devices are run into execution.  In case of lowering the level of concentration below the threshold value, the system must be reset manually by the operator.

Medusa is also supplied with :

control box valves placed inside the storage box, each essentially equipped with a valve of the barrier pneumatically operated with relevant pilot valve, manual valve, safety valve and accumulator safety valves for the refrigerant lines, valves control box placed in the supply room, each with sectioning valves, solenoid and manual, to stop, in case of need the power supply the power lines of the refrigerant box fire alarm, placed in proximity of the two doors of the storage box differential pressure switch for continuous efficiency check of the forced ventilation column indicating abnormal concentration of hazardous gas alarm indicators door or fan, in addition to the microswitch control opening of the doors of the storage box.

Eolo the forced ventilation System

Eolo System consists essentially of a fan soundproof / free multispeed in Ex, rated capacity up to more than 4000 m3 / h, controlled by sensors, pressure differentials. The control system is regulated by a special electrical panel, interfaced with the Medusa monitoring system and with the charging unit Rockall HC
The ventilation pumped by the Eolo system is routed in a pipe appropriately sized according to the factory layout. If the ventilation system ends to work (broken fan motor, accidental clogging ducts etc.) the Medusa system activates a procedure for disarming of the refrigerant pumping systems and the refrigerant charging machine as it no longer guaranteed safety.
The control of the operation takes place by means of differential pressure switches connected to the Medusa system that is dimensioned to detect the presence of air flow in the ventilation areas potentially more critical.

Operation Constraints of the Eolo System :

• The fan must be always in operation, the lower operating speed, when the machines are in operation, so as to maintain a continuous change of air in the working area
• The ventilation flow rate is set at the maximum speed, when one or more sensors detect a gas concentration greater than 15% of the Lower Flammability.
• The fan continues to run at full capacity even when, exceeded the threshold of 30% of the Lower Flammability, the power to the charging unit is cut and is given indication that you are in an emergency situation.