Sierra Monitor Corporation
1991 Tarob Court, Milpitas, CA 95035
(408) 262-6611
(800) 727-4377
(408) 262-9042 - Fax
E-mail: [email protected]
GAS MONITOR
Model 2350-00
Model 2360-00
APPLICABILITY & EFFECTIVITY
This manual provides instructions for the following Sierra Monitor products:
Model
2350-00
2360-00
Description
Gas Monitor - Toxic Only
Gas Monitor - Toxic & Combustible
The instructions are effective for the above models as of March 1, 1999
Instruction Manual Part Number: T10011
Rev. B
Instruction Manual
1.0 PRODUCT DESCRIPTION
1.1 INTRODUCTION
The Model 2350 and 2360 series Gas Monitors provide continuous monitoring of Methane (and other Combustibles)
and Carbon Monoxide gas simultaneously in a confined space to provide safety for personnel and to reduce the hazard
of gas explosion. Both models are designed to operate from a -48 VDC power source typically available in telephone
equipment applications. The monitors are designed for use primarily in telephone equipment cabinets.
Model 2350 has one sensor which is factory calibrated to detect Carbon Monoxide at 100 PPM and has cross sensitivity
to Hydrogen and Methane (CH4). Model 2360 has both a Carbon Monoxide sensor factory calibrated to 100 PPM
Carbon Monoxide and a Combustible Gas sensor calibrated to 5,000 PPM Methane.
Models 2360-00 (figure 1.1) and 2350-00 (figure 1.2) are designed for installation in a customer supplied three position
electrical junction box.
Features of the Models 2350 and 2360 include:
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Local visual and audible alarms.
Ambient temperature change compensation.
Long-life solid state gas and temperature sensors.
-48 VDC operation.
Five alarm relay contacts (2360), four alarm relay contacts (2350).
User selectable active or passive relay alarm test.
Single PC board assembly for easy installation and maintenance.
Alarm test contacts on PC board.
Fused vent relay.
Figure 1.1
Model 2360-00
Model 2350 / 2360 Gas Monitor (3/99)
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Instruction Manual
Figure 1.2
Model 2350-00
1.2GENERALDESCRIPTION
1.2.1. MECHANICAL
The Gas Monitor is comprised of a printed circuit assembly mounted behind a flat cover plate which serves as the
instrument cover when installed into a user supplied, three position electrical gang box (figure 1.3).
Electrical connections for power (-48 VDC) and relays (dry contact alarm activated) are made via screw terminals on the
printed circuit board prior to installation into the gang box.
Calibration adjustment potentiometers are accessible through the cover plate.
•
SENSORS: Gas and temperature compensating sensors are installed onto the printed circuit assembly
and are protected by the cover plate. The sensors can be replaced by removal of the monitor from the
gangbox. The Combustible and Carbon Monoxide sensors are metal-oxide semiconductor type solid state
devices for long life. The electrical resistance of the sensors is inversely proportional to the gas concen-
tration.
•
CONNECTORS: All user connections are made via convenient multi-position screw terminal strip
located on the component side of the printed circuit assembly. Wiring access to the monitor can be
determined by the installer by selecting any hub knockout on the gang box.
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Model 2350 / 2360 Gas Monitor (3/99)
Instruction Manual
Figure 1.3
Models 2350, 2360 Mechanical
1.2.2.ALARM RELAYS
There are five alarm relays (Note: Combustible Gas relay is not installed on Model 2350-00). All are single-pole double-
throw with 6 amp dry non-inductive contacts at 120/240 volts AC.
•
FAILURE RELAY: The failure relay is activated when either gas sensor becomes defective (open sensor
resistance or no heater voltage). The failure relay is normally energized so it will also be activated if the -
48 VDC power fails.
•
•
·
CARBON MONOXIDE RELAY: The Carbon Monoxide Relay is activated when the concentration ex-
ceeds the calibrated threshold setting (100 PPM CO).
COMBUSTIBLE RELAY: The Methane Relay is activated when the concentration of Methane exceeds
the calibrated threshold setting (5000 PPM CH4).
VENTILATION RELAY: The Ventilation Relay is activated when either the CO or CH gas concentra-
4
tion exceed their calibration levels. The common contact of the ventilation relay is fused with a 4 amp
socketed micro-fuse.
·
REMOTE INDICATOR RELAY: The Remote Indicator Relay is activated when either the Failure
Relay or the Ventilation Relay is activated. Any of the following conditions will activate the Remote
Indicator Relay.
*
*
*
*
*
Excess Carbon Monoxide
Excess Methane ( Model 2360 only)
Loss of -48 VDC
Carbon Monoxide sensor failure
Methane sensor failure ( Model 2360 only)
Model 2350 / 2360 Gas Monitor (3/99)
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Instruction Manual
1.2.3. ALARMINDICATORS
The Model 2350 front panel has one audible alarm and four LED annunciation lights.
·
AUDIBLE ALARM: The Audible Alarm will sound when either the CO or CH gas concentration
4
exceeds the respective calibrated threshold levels. The Audible Alarm produces a continuous tone of
2900 Hz at 68 dB.
·
·
POWER FAILUREALARM: The Power-On Failure Alarm consists of a Power-On Lamp (green) which
glows when -48 VDC is present and turns off if power is lost.
CARBON MONOXIDE STATUS LIGHTS: The three CO status lights are: Safe (green), Alarm (red) and
Sensor Failure (red).
The Model 2360 has an additional three LED annunciation lights.
·
COMBUSTIBLE STATUS LIGHTS: The three Combustible status lights are: Safe (green),Alarm (red)
and Sensor Failure (red).
1.2.4. TEST SWITCHES
Test point pairs located on the component side of the printed circuit board (figure 1.4) are provided to allow
testing of the following functions:
·
·
LAMP TEST: When the lamp test pins are shorted together all LED indicators, and the audible alarm,
are activated.
ALARM TEST: When the alarm test pins (W3) are first shorted together then (W4) ares shorted, all LED
indicators, three relays (ventilation, Carbon Monoxide, and Combustible gas) and the audible alarm are
activated.
·
FAILED SENSOR TESTS: When the respective failed sensor test pins are shorted together a failure of
the selected sensor will be simulated. During this test the sensor failure LED indicator will glow and the
Fail and Remote relays will activate.
Figure 1.4
Test Point Locations
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Model 2350 / 2360 Gas Monitor (3/99)
Instruction Manual
2.0 INSTALLATION
2.1 UNPACKINGAND INSPECTION
Remove the gas monitor from its packing container and inspect to insure that all items listed on the packing slip
have been received in good condition.
2.2 INSTALLATIONAND SET-UP
2.2.1. ENCLOSURE MOUNTING
Install a three position gang box (not supplied) on a vertical surface in the location selected for the gas
monitor. Entry for power supply wiring and for alarm contacts should be supplied through conduit connected
to the knock out.
2.2.2. INTERFACE WIRING
D.C. POWER: Pull -48 VDC wiring into the gang box, allow 10” of service loop and strip 1/8” of insulation
to prepare for connection to the monitor.
ALARM RELAYS: Pull any required alarm relay wiring into the gang box, allow 10” of service loop and
strip 1/8” of insulation for connection to the monitor.
WIRING CONNECTIONS: Using Figure 2.1 as a guide, connect the -48 VDC wiring and the alarm relay
wiring to the appropriate terminal points. Open the terminals by turning the locking screw counterclockwise,
insert the wire so that the full 1/8” strip is inside the connector and close the connector securely by turning the
screw clockwise.
Figure 2.1
Interface Wiring Terminal Positions
2.2.3. START-UP
POWER ON: Apply power to the -48 VDC wiring. After a short pause the audible alarm will sound and the
alarm lights will light on the front panel. The alarms will stabilize within five minutes at which time the
audible will cease and the “safe” lights on the front panel will light.
MONITOR STABILIZATION: During the first 24 hours of operation the sensors may be unstable and
alarms may occur. Alarms should be ignored during this period and remote annunciation should not be
activated.
Model 2350 / 2360 Gas Monitor (3/99)
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Instruction Manual
3.0 OPERATION
The Model 2350 and 2360 require no operator intervention except for periodic calibration. The following
information can be followed to insure that the initial installation and external wiring is correct.
3.1 STATUS INDICATION
Table 1 describes status of each indicator under various conditions:
CONDITION
LIGHTS
RELAYS
AUDIBLE
System
C O
Methane
Power Safe Alarm Fail
Safe Alarm Fail
C O
CH4
ON
Fail Vent Remote
POWER ON
Safe
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
CO Alarm
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
CH Alarm
4
CO Fail
ON
ON
ON
CH Fail
4
TEST LIGHTS
Active
Passive
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
TABLE 1
STATUS INDICATORS
3.2 FUNCTION TESTS
The following function tests can be performed to confirm the conditions described in Table 1. Use Figure 1.4
(page 4) to locate test points.
·
TEST LIGHTS: Short the “Test Lights” test points and check that all panel lights turn “ON” and that the
audible alarm turns on. If the “active “ relay test is used the Carbon Monoxide, Combustible and Vent relays
will activate during this test.
·
·
FUNCTION TEST: Apply gas from a cigarette lighter (without flame) or other high concentration source to
the Methane sensor and check that the Combustible Alarm light goes on.
FAILED SENSOR TESTS: When the respective failed sensor test pins are shorted together a failure of the
selected sensor will be simulated. During this test the sensor failure LED indicator will glow and the Fail and
Remote relays will activate.
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Model 2350 / 2360 Gas Monitor (3/99)
Instruction Manual
4.0 CALIBRATION
4.1 FREQUENCY OF CALIBRATION
The manufacturer recommends that the Model 2350 or 2360 be calibrated as follows:
·
·
During the first three months of operation: Calibrate every 30 days.
Upon completion of three months operation: Calibrate every 90 days.
4.2 CALIBRATION PROCEDURE
PREPARATION: Locate the two (one for Model 2350) span adjusting potentiometers which are visible on the
front panel. Adjustment of these potentiometers raises and lowers the sensitivity of the respective gas sensor. Also
locate the two LED alarm indicators for the respective gases.
CALIBRATION - METHANE: Apply 5000 PPM Methane calibration gas at 50 cc/minute to the combustible
sensor and watch for the alarm indicator to turn on. If the indicator turns on within approximately five seconds of
application of the gas and turns off within approximately five seconds of removal of the gas the sensor is correctly
calibrated. If the indicator fails to turn on, keep the gas on the sensor and adjust the potentiometer clockwise until
the calibration indicator turns on. If the indicator turns on too quickly and stays on for too long after removal of
the gas, adjust the potentiometer counter-clockwise to decrease the sensitivity and repeat the calibration process.
CALIBRATION - CARBON MONOXIDE: Apply Carbon Monoxide calibration gas to the CO sensor. (100 PPM
CO at 50 cc/minute). Watch for the alarm indicator to turn on. If the indicator turns on within approximately one
minute of application of the calibration gas and turns off within approximately one minute after removal of the
calibration gas the sensor is correctly calibrated. Adjust the sensitivity as described in the preceding paragraph.
NOTE: Sierra Monitor Corporation recommends using the Gas Sensor Calibrator, Model 1200-26, for calibration
of Combustible and Carbon Monoxide sensors.
4.3 MAINTENANCE
Except for periodic calibration as described above, no routine maintenance is required. The following items may
require replacement due to age and deterioration:
SENSOR: To remove a sensor, first turn off the power to the monitor and remove it from the gang box (four screws,
two on each end of the cover plate). Remove the cover plate by unscrewing the remaining four screws on the cover
plate. The individual sensors are plugged into the PC board and can be lifted out and replaced. Note that there is
no special orientation required when the six pin sensor is plugged into the socket. Reassemble the monitor by
reversing the above procedure, apply power and allow 24 hours for stabilization prior to re-calibration.
NOTE TO INSTALLERS:
Field data shows that the Model 2350 & 2360 Gas Monitors operates well in the installed, continu-
ous operation cabinet. This is because the environmental conditions in the cabinet are relatively
stable.
Various minor difficulties occur during the installation and initial check-out due to major variations
in climatic conditions and due to the inspection occurring very quickly after the monitor has been
turned on.
Upon initial turn-on the monitor requires a stabilization period which varies based on the amount of
time it has been stored and the temperature during stabilization. Longer storage times and colder
temperatures increase the stabilization time required. As the specified lower operating temperature
o
of the monitor is 32 F it may not be possible to perform function checks in assembly areas where the
temperature is below freezing.
Model 2350 / 2360 Gas Monitor (3/99)
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Instruction Manual
5.0 SPECIFICATIONS & SPARE PARTS
SPECIFICATIONS
INPUT POWER
-48 VDC
4 Watts Max.
32 to 104 F (0 - 40 C)
o
o
OPERATING TEMPERATURE
CALIBRATION RANGE
Carbon Monoxide: 50 - 200 PPM
Methane: 2,500 - 12,500 PPM (5% - 25% LEL)
Carbon Monoxide: 100 PPM
FACTORY CALIBRATION
Methane 5000 PPM
RESPONSE TIME
ENCLOSURE
CONNECTORS
OUTPUT RELAYS
Less than 30 Seconds
None - Fits 3 position electrical gang box.
Screw clamp terminal block, 14-22 AWG, 10 A @ 300 VAC
Five SPDT (FORM C) -2360, Four SPDT (Form C) - 2350
6 AMP Non-Inducting @120/240VAC
1/8 HP Load
GAS SENSORS
TEMPERATURE SENSOR
AUDIBLEALARM
FUSE
SIZE
WEIGHT
Solid-state metal-oxide semiconductor sensors .
Solid state sensors
68db at 2900 Hz
2 Amp (main), 4 Amp (vent relay)
9” X 5” X 1.5” (22.9 X 12.7 X 3.8 cm)
3 lbs. (1.3 kg)
SPARE PARTS LIST
CALIBRATIONACCESSORIES
Model No.
1200-26
1290-03
1290-05
Description
Gas Sensor Calibrator w/2 gas cylinders
Gas Cylinder - Methane 5000 PPM
Gas Cylinder - Carbon Monoxide 100 PPM
MODEL 2350 and 2360 SERIES SPARE PARTS
Part No.
Description
SPJ33003
SPJ33007
SPJ49088
SPJ49085
Sensor, Combustible
Sensor, Carbon Monoxide (50-200 PPM)
Fuse, 2 Amp, Micro Package - Main F2
Fuse, 4 Amp, Micro Package - Vent F1
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Model 2350 / 2360 Gas Monitor (3/99)
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Instruction Manual
6.0 LIMITED WARRANTY
SIERRA MONITOR CORPORATION warrants its products to be free from defects in workmanship or material under
normal use and service for two years after date of shipment. SMC will repair or replace without charge any equipment
found to be defective during the warranty period. Final determination of the nature and responsibility for defective or
damaged equipment will be made by SMC personnel.
All warranties hereunder are contingent upon proper use in the application for which the product was intended and do
not cover products which have been modified or repaired without SMC approval or which have been subjected to
accident, improper maintenance, installation or application, or on which original identification marks have been removed
or altered. This Limited Warranty also will not apply to interconnecting cables or wires, consumables (ie. calibration
gases, batteries, sensors), nor to any damage resulting from battery leakage.
In all cases SMC’s responsibility and liability under this warranty shall be limited to the cost of the equipment. The
purchaser must obtain shipping instructions for the prepaid return of any item under this warranty provision and
compliance with such instruction shall be a condition of this warranty.
Except for the express warranty stated above, SMC disclaims all warranties with regard to the products sold hereunder
including all implied warranties of merchantability and fitness and the express warranties stated herein are in lieu of all
obligations or liabilities on the part of SMC for damages including, but not limited to, consequential damages arising out
of/or in connection with the use or performance of the product.
Model 2350 / 2360 Gas Monitor (3/99)
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