ENMET ISA-M User Manual
ENMETENMET Corporation
PO Box 979
Ann Arbor, MI 48106-0979
ISA – MISA – M
OPERATION & M AINTENANCE
MANUAL
80003-027
04/27/95
MCN-204, 10/20/98
MCN-285, 11/20/02
Table of Contents
1.0 INTRODUCTION................................................................................................................................1
1.1 Unpack ................................................................................................................................................................................1
1.2 Check Order.......................................................................................................................................................................1
1.3 Serial Numbers .................................................................................................................................................................. 1
1.4 Read Manual ...................................................................................................................................................................... 1
2.0 F EATURES IF THE ISA – M................................................................................................................2
2.1 External Feature of the ISA – M.....................................................................................................................................2
2.2 Internal Features of the ISA – M .................................................................................................................................... 3
4.0 INSTALLATION ................................................................................................................................4
4.1 Mounting and Power Hook-up........................................................................................................................................4
4.2 Sensor Location ................................................................................................................................................................. 5
4.3 Sensor Hook-up.................................................................................................................................................................6
4.4 Sensor Heater Voltage......................................................................................................................................................7
5.0 OPERATION....................................................................................................................................8
5.1 Warm – Up ......................................................................................................................................................................... 8
5.2 Precautions.........................................................................................................................................................................8
5.3 Rough Test.........................................................................................................................................................................8
6.0 ROUTINE GAS TEST AND RECALIBRATION...........................................................................................9
6.1 Test......................................................................................................................................................................................9
6.2 To Recalibrate .................................................................................................................................................................. 10
7.0 MAINTENANCE.............................................................................................................................. 11
4.1 Basic Troubleshooting...................................................................................................................................................11
7.2 Sensor Replacement........................................................................................................................................................11
7.3 Replacement Part Numbers...........................................................................................................................................12
8.0 SPECIFICATIONS ........................................................................................................................... 12
8.1 Options and Variations...................................................................................................................................................12
9.0 WARRANTY............................................................................................................................... 13
9.1 Repair of Certain Units .................................................................................................................................................. 13
List of Figures and Tables
FIGURE 1: EXTERNAL FEATURES OF THE ISA – M.....................................................................................2
FIGURE 2: INTERNAL FEATURES OF THE ISA – M......................................................................................3
FIGURE 3: MOUNTING DIMENSIONS OF THE ISA – M..................................................................................4
TABLE 1: HEAVIER THAN AIR..................................................................................................................5
TABLE 2: LIGHTER THAN AIR..................................................................................................................5
TABLE 3: SAME DENSITY AS AIR.............................................................................................................5
FIGURE 4: INTERNAL VIEW OF S ENSOR WIRING.........................................................................................6
TABLE 4: RECOMMENDED WIRE GAUGE...................................................................................................6
FIGURE 5: EXPOSING A S ENSOR TO TEST OR CALIBRATION GAS .................................................................9
TABLE 5: APPROXIMATE ALARM TIME...................................................................................................10
Reference information:
NOTE: [important information about use of instrument – if not followed may have to redo some steps.]
CAUTION: [affects equipment – if not followed may cause damage to instrument, sensor etc…]
WARNING: [affects personnel safety – if not followed may cause bodily injury or death.]
ISA – M ENMET Corporation
1.0 Introduction1.0 Introduction
The ENMET Model ISA-M detector/alarm is an all solid-state electronic gas-detecting instrument that minimizes the
risk of harm or death to people who are exposed to potentially hazardous gas environments. It continuously monitors
for combustible or toxic gases and warns of a dangerous gas situation with enough time to take action to avoid harm.
Audio (horn) and visual (light) alarms are calibrated to trigger at both high and low level gas concentrations.
The ISA-M uses a gas-sensitive Metallic Oxide Semiconductor (MOS) sensing element which reacts to toxic and
combustible gas molecules. An oxidation reaction occurs on the sensor surface when contaminants are present. The
oxidation reaction changes the sensor's electrical resistance which then triggers the alarm circuitry when the
concentration of gas goes beyond a preset level.
The sensor can be located up to 1000 feet from the circuit enclosure and connected electrically by wire or cable.
NOTE: All specifications stated in this manual may change without notice.
1.1 Unpack
Unpack the ISA – M and examine it for shipping damage. If such damage is observed, notify both ENMET customer
service personnel and the commercial carrier involved immediately.
Regarding Damaged Shipments
NOTE: It is your responsibility to follow these instructions. If they are not followed, the carrier will
not honor any claims for damage.
q This shipment was carefully inspected, verified and properly packaged at our company and delivered to the
carrier in good condition.
q When it was picked up by the carrier at ENMET, it legally became your company’s property.
q If your shipment arrives damaged:
• Keep the items, packing material, and carton “As Is.” Within 5 days of receipt, notify the carrier’s local office
and request immediate inspection of the carton and the contents.
• After the inspection and after you have received written acknowledgment of the damage from the carrier,
contact ENMET Customer Service for return authorization and further instructions. Have your Purchase Order
and Sales Order numbers available.
q ENMET either repairs or replaces damaged equipment and invoices the carrier to the extent of the liability
coverage, usually $100.00. Repair or replacement charges above that value are your company’s responsibility.
q The shipping company may offer optional insurance coverage. ENMET only insures shipments with the
shipping company when asked to do so in writing by our customer. If you need your shipments insured, please
forward a written request to ENMET Customer Service.
Regarding Shortages
If there are any shortages or questions regarding this shipment, please notify ENMET Customer Service within 5 days
of receipt at the following address:
ENMET Corporation
680 Fairfield Court
Ann Arbor, MI 48108
734-761-1270 734-761-3220 Fax
1.2 Check Order
Check, the contents of the shipment against the purchase order. Verify that the ISA – M is received as ordered. Each
ISA – M is labeled with its target gas. If there are accessories on the order, ascertain that they are present. Check the
contents of calibration kits. Notify ENMET customer service personnel of any discrepancy immediately.
1.3 Serial Numbers
Each ISA – M is serialized. These numbers are on tags on the equipment and are on record in an ENMET database.
1.4 Read Manual
Read this manual carefully and thoroughly before installing and operating this instrument.
1
ENMET Corporation ISA – M
Switch Indicator
Audio Alarm
Visual Alarm
Power Indicator
Visual Alarm
2.0 Features if the 2.0 Features if the ISA – M
2.1 External Feature of the ISA – M
Figure 1 shows the ISA-M control unit which contains the electronic circuitry and controls. Main features are listed below.
Feature Description
Meter
Operation Switch A rotary switch for:
Switch Indicator
(Red)
Audio Alarm(Horn) Audio alarm (2900 Hz, 95 dB at 2 ft.). The audio alarm is activated when the unit is in alarm.
Power Indicator
(Green)
Visual Alarms Amber: Visual alarm (steady light). When this lamp is on, power to the unit is on and the unit
This is a non-linear device. Do not infer exact readings from unmarked regions of the meter
scale.
The scale is marked in units of measure for the gas depending on instrument calibration.
§ PPM (Parts Per Million) for toxic gases
§ % LEL (Lowest Explosive Level) for combustible gases
§ OPERATE – Normal Operation
§ HORN OFF – Disable Audio Alarm
§ PURGE ON – (sensor temperature control) Purge ON to clean (purge) sensor surface of
absorbed contaminants (sensor hot).
When the light is on, Indicates OPERATION SWITCH is not in OPERATE
When the light is on, the unit is operating and is not in alarm.
When this light is off, the unit is in alarm OR power to the unit has been interrupted.
is in low alarm.
Red: Visual alarm (steady light). When this lamp is on, power to the unit is on and the unit is
in high alarm.
(Green)
(Red)
(Amber)
(Red)
Operation Switch
Meter
(Horn)
Power Cord
Figure 1: External Features of the ISA – M
2
ISA – M ENMET Corporation
Suggested wiring configuration for Utilizing Relay Contacts
Common
Normally
Manual On/Off
110 Vac
12 V
Internal Relay
Contacts
Purge Adjust
2.2 Internal Features of the ISA – M
Figure 2 shows the circuit board and terminal blocks housed inside the hinged oiltight control unit. Specific relays and
adjustments are defined in the table below.
Feature Description
Internal Relay Contacts
Potentiometers(POT) The unit has five potentiometers. These vary circuit resistances and are essential to
Heater Adjust
(RV32)
Low Level Alarm
(RV35)
High Level Alarm
(RV34)
Meter Adjust
(RV33)
Purge Adjust
(RV38)
There is one relay for each alarm level. Relays can be used to activate an external remote
alarm signal when a hazardous gas level is detected, or when the ac or dc power is
interrupted. These are double-pole relays with terminals "normally open", "normally
closed" and "common" (see figure 3 for relay contact hook-up).
calibration procedures. These potentiometers are described below.
For adjusting the sensor heater voltage (see section 4.4)
For low-level alarm adjustment (calibration, see section 6.2).
For high-level alarm adjustment (calibration, see section 6.2).
To adjust and set the meter for appropriate gas response during calibration. (See section 6.2)
For adjusting the sensor heater voltage on units that require periodic purging (cleaning) of
the sensor. (See section 4.4)
(manual on/off switch is suggested; user supplied component)
Closed
Contact
Contact
Black
Power supply Outside
of Control Unit
Switch
Horn
White
Non-Latching Relay contacts:
Identified below is the non-powered
(power to unit is off), alarm positions of
the non-latching relay contacts.
Terminal Block 2 see Figure 5
Relay 1 High Alarm
Relay 2 Low Alarm
NOTE: N.C.= normally closed
N.O.= normally open
Low-level Alarm
(POT RV35)
Input
DC
Meter Adjust
(POT RV33)
High-level Alarm
(POT RV34)
Heater Adjust
(POT RV32)
(POT RV38)
110/115
or
220/230*
*See section 4.2
Figure 2: Internal Features of the ISA – M
3
Loading...