mechanical room entrance. The exterior light will
be provided with a sign that warns personnel
entering the mechanical room of a refrigerant
release and that a SCBA is required to enter. If
applicable to the installation, include an audible
alarm on the exterior of the mechanical room.
Include the electrical design for the alarm system
on the drawings.
As an additional item, ASHRAE 15 states that
open-flame devices (i.e., boilers, etc.) cannot be
installed in the same area as a refrigeration
system, unless either combustion air for the
open-flame device is ducted straight from outside to
the device; or the alarm relay from the detector is
used to automatically shutdown the combustion
process in the event of refrigerant leakage.
Indicate all applicable alarm controls on the
drawings.
Delete the information in the last bracketed
sentences if an EMCS is not applicable to the design.
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Detector shall be the continuously-operating, halogen-specific type.
Detector shall be appropriate for the refrigerant in use. Detector shall
be specifically designed for area monitoring and shall include [a single
sampling point] [[_____] sampling points] installed where indicated.
Detector design and construction shall be compatible with the temperature,
humidity, barometric pressure and voltage fluctuations of the operating
area. Detector shall have an adjustable sensitivity such that it can
detect refrigerant at or above 3 parts per million (ppm). Detector shall
be supplied factory-calibrated for the appropriate refrigerant(s).
Detector shall be provided with an alarm relay output which energizes when
the detector detects a refrigerant level at or above the TLV-TWA (or
toxicity measurement consistent therewith) for the refrigerant(s) in use.
The detector's relay shall be capable of initiating corresponding alarms
and ventilation systems as indicated on the drawings. Detector shall be
provided with a failure relay output that energizes when the monitor
detects a fault in its operation. [Detector shall be capable with the
facility's energy management and control system (EMSS). The EMCS shall be
capable of generating an electronic log of the refrigerant level in the
operating area, monitoring for detector malfunctions, and monitoring for
any refrigerant alarm conditions.]
2.8.2
Refrigerant Relief Valve/Rupture Disc Assembly
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NOTE: ASHRAE 15 requires refrigeration systems to
be protected with a pressure-relief device that will
safely relieve pressure due to fire or other
abnormal conditions. A relief valve/rupture disc
assembly is the optimum solution. The rupture disc
will provide visual indication of a release while
also providing immediate shutoff once a safe
pressure is achieved.
Designer will indicate on the drawings the location
of each new relief valve/rupture disc assembly as
SECTION 15620A
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