ASHRAE 15-2001 and Mechanical and Fire Code Requirements For the Monitoring of Leaked Refrigerant

The requirements for the monitoring for Leaked Refrigerants within an HVAC or Refrigeration Machinery Room typically are:

    1.  Each refrigerating machinery room shall contain a detector for refrigerant gas or vapor to be located in an area where refrigerant from a leak will concentrate

Genesis International offers two unique sensing technologies for the detection of leaked refrigerant:

    The SHERLOCK^TM Infra-Red Refrigerant Gas Sensor

    The SHERLOCK^TM Solid State Refrigerant Gas Sensor

Each sensing technology is designed to be placed into the area where refrigerant from a leak will likely concentrate.  The sensors produce an analog signal that can be monitored by a SHERLOCK^TM Refrigerant Gas Monitoring Panel or by a control system supplied by others.

    2.  The refrigerant gas detection system shall:

        - Actuate an alarm

        - Activate mechanical ventilation

        - Shutdown any combustion process or "high heat" producing devices.

The SHERLOCK^TM Refrigerant Gas Monitoring Panels were designed to monitor the analog signal from either the SHERLOCK^TM Infra-Red Refrigerant Gas Sensor, the SHERLOCK^TM Solid State Refrigerant Gas Sensor or analog output producing refrigerant gas sensors manufactured by other suppliers.

Each panel is designed to activate relay outputs that can be connected to activate and control a number of alarming circuits, to include:

    - Audio and Visual Alarms

    - Mechanical Ventilation

    - The Shutdown of mechanical devices such as chillers, boilers, pumps, etc....

    - Interface with Building Alarm Systems

The SHERLOCK^TM Refrigerant Gas Monitoring Panels are available with an optional Analog Output Module and Zone Isolation Relay modules.

Analog Output Module - This option is currently available only for the Sherlock 102, 204, 404 or 804 Control Systems.  The AO option provides one analog output circuit for each sensor.  This output produces a configurable signal that will correspond its assigned refrigerant detection sensor's signal.  Output signal can be configured to be either 4-20ma (250Ohm maximum), 0-5VDC or 0-10VDC.

Zone Isolation Relay Modules - This options provides an additional one or two (Model specific) relays for each sensor monitored.  The Zone Isolation Relays will activate its assigned sensor exceeds the relay's programmed alarm level.

    3.  Alarming Requirements

        - Audible and Visual Alarm - Visible throughout the entire space, loud enough to be heard over the noise of the mechanical equipment

        - Located inside the machinery room to facilitate evacuation

        - Located outside each entrance to the refrigerating machinery room to prevent access into a hazardous environment.

        - Alarms are to be manually reset only, with the reset device located outside of the machinery room.

Genesis International offers a substantial array of products for the enunciating of a refrigerant leaks alarm.  See Alarm Indication Equipment

    4.  Emergency Purge Ventilation Requirements.  The Refrigerant Leak Monitoring shall activate an emergency ventilation system to evacuate the air from within the machinery room

The SHERLOCK^TM Refrigerant Gas Monitoring Panels provide alarm relay contacts that can be connected to activate Emergency Purge Ventilation equipment.  The SHERLOCK prevents the short cycling of the ventilation system by either requiring manual reset of the alarm relay or by offering a reset delay for the shutdown of the ventilation system.  This reset delay will provide a minimum runtime for the ventilation fan before it shuts off.

    5.  Combustion "High Heat" Producing Device Shutdown Requirements.  Should any device that produces either a surface temperature of greater than 800 deg F or have an open flame have the ability to come into contact with refrigerant leaked into the machinery room, that device shall be shutdown upon the activation of the Refrigerant Leak Monitor Alarms.

The SHERLOCK^TM Refrigerant Gas Monitoring Panels provide alarm relay contacts that can be connected to shutdown any combustion systems or high heat producing appliances.

    6.  Providing of Remote Controls for the Ventilation and Mechanical Equipment.  Many mechanical codes and ASHRAE 15 are requiring a control station consisting of at least an ON-OFF switch (a few codes specify "break glass type") be provide immediately outside of the machinery room.  This control station will:

        - Manually start the Ventilation System into the Emergency Purge CFM levels.

        - Manually shutdown all electrically energized devices within the machinery rooms, excluding the Refrigerant Detection System and the Ventilation System.

        - Indication panel to show the operational status of the ventilation system.  This panel contains two indictor lights to show that the ventilation system is either drawing air out of the machinery room (Flow) or is off or has failed (No Flow).

Genesis International stocks a number of accessories for the compliance of ANSI/ASHRAE 15-2001 and various Mechanical and Fire Codes.

Break Glass Switch - This switch is suitable for meeting the requirements for manual control of the ventilation fan and for the shutting down of the mechanical equipment

See Alarm Indication Equipment

Genesis International, Inc. reserves the right to change product specifications and availability without notice.

Contact a factory representative for additional information on this and any other products.

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