Genesis SHERLOCK 102 Operation Manual Download Page 6

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44-00-0297

SHERLOCK

102/202 REV. 4.1 05-02-15

The American Society of Heating, Refrigeration, and Air-
Conditioning Engineers, Inc Standard

ANSI/ASHRAE 15-

2004 Safety Code for Mechanical Refrigeration

states:

8.11.2 Each machinery room shall contain a detector,
located in an area where refrigerant from a leak will
concentrate, which shall activate an alarm and mechan-
ical ventilation ....

The International Conference of Building Official

Uniform

Mechanical Code, 2000

states:

SECTION 1121 - DETECTION AND ALARM
SYSTEM

1121.1 General.  Alarm shall be activated whenever the
refrigerant  vapor  Permissible  Exposure  Limit  (PEL)
is  exceeded.    In  other  than  machinery  rooms,  such
systems  shall  also  automatically  stop  the  flow  of
refrigerant  to  evaporators  within    the  space  and  stop
the  flow  of  refrigerant  in  all  supply  lines  leaving  the
machinery  room  whenever  the  refrigerant  vapor  con-
centration  is  detected  at  or  above  50  percent  of  the
IDLH [Immediately Dangerous to Life or Health] or 25
percent of the LEL (lower explosive limit).

The

SHERLOCK

102, and 202 Refrigerant Gas Monitor was

designed to meet these and other requirements.

Monitoring Panel

The

SHERLOCK

102 and 202 Control Module is an ETL

listed,  hard  wired,  permanently  mounted  electronic  control
panel  that  is  capable  of  monitoring  the  analog  output  signal
of  up  to  two

SHERLOCK

Refrigerant Gas Sensors or one

SHERLOCK

Refrigerant Gas Sensors and one

SHERLOCK

Oxygen Depletion Sensors.  The Control Module will activate
four Form C SPDT relay contacts based upon the programmed
alarm setpoints of each sensor. The relays are referred to as K1,
K2  for  the  first  alarm  level  and  K3,  K4  for  the  second  alarm
level.  There is optional zone isolation alarm relay (K5 & K6)
for each Sensor. The Control Module can be located in the area
to be monitored, or in a separate location, typically outside of
the monitored room.

Monitoring Points

Each monitoring point consists of an analog signal generat-
ing sensor connected to the control module via discrete, three
conductor cable. Each sensor can be mounted up to 1000 feet
(longer run with special cable) away in locations where leaked
refrigerant is likely to concentrate.

THE SHERLOCK REFRIGERANT GAS MONITOR

The Sherlock gas sensors are available in three varieties:

Ceramic Metal Oxide Semiconductor (CMOS) or Solid
State Sensor
Non-Dispersive, Pyro-Electric Infrared Sensor.
Ammonia & Oxygen Depletion Electro-chemical Sensor.

CMOS or Solid State Sensor

The

SHERLOCK

CMOS (Solid State) Sensor utilizes a Tin

-Oxide  filiment,  heated  to  400°F,  to  detect  the  presence  of
oxygen molecules within the air.  At this temperature, Oxygen
molecules cling to the filament.  When a molecule of an organic
compound or a halogen strikes the filament, it displaces an oxy-
gen molecule thus increasing the resistive value of the filament.
This  change  in  resistance  is  processed  by  the  sensor  circuitry
to  produce  an  analog  output  signal,  which  sent  to  the  Control
Module as the sensor reading.

Sensors are available in configurations that detect refrigerant
gases by class; CFC/HCFC, HFC and Ammonia. These sensors
produce a non-linear output signal that generally corresponds to
the concentration of refrigerant in the air.

NOTE:  These sensors, due to their nature, are susceptible
to detection of non-refrigerant gases and cannot distinguish
the presence of different refrigerant gases, only that there is
a  gas  present.    The  CMOS  sensor  will  detect  high  concen-
trations of gasoline, diesel, and propane exhaust and fumes
from  solvents,  paints,  cleansers,  and  others  (Please  call
Genesis Customer Support for more information).

Infrared Sensor

The

SHERLOCK

Non-Dispersive, Pyro-Electric Infrared Sensor

utilizes a detection chamber with an infrared light emmiter and
an infrared Pyro-Electric photo sensor with a filtering lens.  The
IR  sensor  will  detect  the presence  of  a  certain  gas by  measur-
ing the change in the intensity of light measured by the photo
sensor.  Each sensor is designed to detect only infrared light of
a  specific  wavelength  corresponding  to  the  refrigerant  gas  to
be monitored. This change in light intensity is processed by the
sensor circuitry to produce an analog output signal, which sent
to the Control Module as the sensor reading.

Sensors are available in specific configurations that detect cer-
tain refrigerant gases. Check with Genesis International for a
current list a available gas sensors.

These sensors produce a linear output signal that corresponds to
the concentration of refrigerant in the air. The Control Module
will translate the analog signal and display the readings in Parts
per Million values.

Electro-Chemical Ammonia Sensor

The

SHERLOCK

Electro-Chemical Ammonia Sensor utilizes

a chemical cell to determine the concentration of Ammonia in
the  air.    The  chemical  cell  produces  small  chemical  reaction
with Ammonia molecules, thus producing a voltage drop across
the  cell.    When  the  concentration  of  Ammonia  goes  up,  the
voltage drop across the cell changes.  This change in voltage is

INTRODUCTION

Genesis International
ETL Label P/N 44-0313
3.0 x 1.25 in

Shown is a Negative Image. Actual shall have
background black and lettering and logos white.

Label shall be suitable for weather conditions and cleansers..

3.00"

1.2

ETL Label Plate
44-0313
10-30-02 Rev A.

ETL Listed

Conforms To UL Std. 3111-1

Certified To CAN/CSA

C22.2 Std. No. 1010.1

9800995