MSA ZGARD C Instruction Manual

Controllers

Instruction Manual

THIS MANUAL MUST BE CAREFULLY READ BY ALL INDIVIDUALS WHO HAVE OR WILL HAVE
THE RESPONSIBILITY FOR INSTALLING, USING OR SERVICING THIS PRODUCT. Like any piece
of complex equipment, this product will perform as designed only if installed, used and serviced in
accordance with the manufacturer’s instructions. OTHERWISE, IT COULD FAIL TO PERFORM AS
DESIGNED AND PERSONS WHO RELY ON THIS PRODUCT FOR THEIR SAFETY COULD
SUSTAIN SEVERE PERSONAL INJURY OR DEATH.

The warranties made by Mine Safety Appliances Company with respect to these Products are voided if the
products are not installed, used and serviced in accordance with the instructions in this user guide. Please
protect yourself and others by following them. We encourage our customers to write or call regarding this
equipment prior to use or for any additional information relative to use or repair.

Instrument Division 1-800-MSA-INST or FAX [phone]

MSA International [phone] or FAX [phone]

In Canada 1-800-267-0672 or FAX [phone]

© Mine Safety Appliances Company 2005 - All Rights Reserved

MINE SAFETY APPLIANCES COMPANY
PITTSBURGH, PENNSYLVANIA 15230

REV 1.2 August 2008 10063483

WARNING

MSA

Permanent Instrument Warranty

1. Warranty- Seller warrants that this product

will be free from mechanical defect or faulty
workmanship for a period of eighteen (18)
months from date of shipment or one (1) year
from installation, whichever occurs first,
provided it is maintained and used in
accordance with Seller’s instructions and/or
recommendations. This warranty does not
apply to expendable or consumable parts
whose normal life expectancy is less than one
(1) year such as, but not limited to, non­rechargeable batteries, filament units, filter,
lamps, fuses etc. The Seller shall be released
from all obligations under this warranty in the
event repairs or modifications are made by
persons other than its own or authorized
service personnel or if the warranty claim
results from physical abuse or misuse of the
product. No agent, employee or representative
of the Seller has any authority to bind the
Seller to any affirmation, representation or
warranty concerning the product. Seller makes
no warranty concerning components or
accessories not manufactured by the Seller,
but will pass on to the Purchaser all warranties
of manufacturers of such components. THIS

WARRANTY IS IN LIEU OF ALL OTHER
WARRANTIES, EXPRESSED, IMPLIED OR
STATUTORY, AND IS STRICTLY LIMITED
TO THE TERMS HEREOF. SELLER

SPECIFICALLY DISCLAIMS ANY
WARRANTY OF MERCHANTABILITY OR OF
FITNESS FOR A PARTICULAR PURPOSE.

2. Exclusive Remedy- It is expressly agreed

that Purchaser’s sole and exclusive remedy for
breach of the above warranty, for any tortious
conduct of Seller, or for any other cause of
action, shall be the repair and/or replacement
at Seller’s option, of any equipment or parts
thereof, which after examination by Seller is
proven to be defective. Replacement
equipment and/or parts will be provided at no
cost to Purchaser, F.O.B. Seller’s Plant.
Failure of Seller to successfully repair any
nonconforming product shall not cause the
remedy established hereby to fail of its
essential purpose.

3. Exclusion of Consequential Damage-

Purchaser specifically understands and agrees
that under no circumstances will seller be liable
to purchaser for economic, special, incidental
or consequential damages or losses of any
kind whatsoever, including but not limited to,
loss of anticipated profits and any other loss
caused by reason of non operation of the
goods. This exclusion is applicable to claims
for breach of warranty, tortuous conduct or any
other cause of action against seller.

General Warnings

WARNING

1. The ZGARD C controllers described
in this manual must be installed,
operated, and maintained in strict
accordance with the labels,
cautions, warnings, instructions,
and within the limitations stated.

2. The ZGARD C controllers must not
be installed in outdoor areas or in
locations where explosive
concentrations of combustible
gases or vapors might occur in the
atmosphere: Class 1, Group A, B,
C, and D areas as defined by the
NEC. Because the controller is not
explosion-proof, it must be located
in non-hazardous areas.

3. Do not paint the ZGARD C
controllers.

4. The only absolute method to assure
the proper overall operation of a
gas detection instrument is to check
it with a known concentration of the
gas for which it has been calibrated.
Consequently, a calibration check
must be included as part of the
installation and as a routine
inspection of the system.

5. Use only genuine MSA replacement
parts when performing any
maintenance procedures provided
in this manual. Failure to do so may
seriously impair instrument
performance. Repair or alteration of
the ZGARD C controllers, beyond
the scope of these maintenance
instructions or by anyone other than
authorized MSA service personnel,
could cause the product to fail to
perform as designed, and persons
who rely on this product for their
safety could sustain serious
personal injury or death.

6. The ZGARD C controllers must be
installed, located and operated in
accordance to all applicable codes.
These codes include, but are not
limited to, the National Fire
Prevention Code and National
Electric Code.

7. Do not exceed the relay contact
ratings listed in this manual.
Otherwise, the relay operation may
fail, which can result in personal
injury or death.

Failure to comply with the above warnings

can result in serious personal injury or

death.

Table of Contents

Section 1

Section 2 General Installation Guidelines

Section 3 ZGARD C 1-Channel Controller, General Information, Operating Specifications and Features

Installation and Set-up Display Mode

Relay Function, Setting up the Warning and Alarm Delays

Audible Alarm Device Setting, Warning and Alarm Set-Points

Section 4 ZGARD C 4-Channel Controller, General Information, Operating Specifications and Features

Installation and Set-up Display Mode, Number of Remote Sensor Inputs

Relay Function, Setting up the Warning and Alarm Delays

Audible Alarm Device Setting, Warning and Alarm Set-Points

Alarm Relay Latch Set-up, Analogue Output Adjustment

Section 5 Start-Up Procedure

Section 6 Parts List

Drawings ZGARD C 1-Channel Controller

106956-1A

106956-2A

106957-1A

106957-2A

General Information

Alarm Relay Latch Set-up, Analogue Output Adjustment

Installation Outline for 4-20mA Analog Signal Type sensors

Installation Outline for RS485 Digital Signal Type sensors

ZGARD C 4-Channel Controller

Installation Outline for 4-20mA Analog Signal Type sensors

Installation Outline for RS485 Digital Signal Type sensors

1.0

2.0

3.0

3.1

3.2

3.3

3.4

4.0

4.1

4.2

4.3

4.4

5.0

6.0

Section 1

ZGARD C Controllers

General Information

The ZGARD C Controllers are microprocessor-based monitoring systems designed to interface with remote
gas sensors and perform user configured control functions for surveillance, activate ventilation equipment,
personnel alert or alarm indication. The controllers feature audible and visual status indicators with relay
outputs. MSA ZGARD S or GS sensor-transmitters are available to detect a wide variety of gases including
Carbon Monoxide, Carbon Dioxide, Nitrogen Dioxide and Refrigerants.

The table below provides the distinctive features of the ZGARD C Controllers. This is a quick guide for
determining the functionally, capability and configuration of each controller.

ZGARD C CONTROLLER MODEL 1 CHANNEL

Number of Remote Sensors

Power LED (Green)

Digital Readout

Audible Alarm

Relay Mode, Energized
De-Energized

(Jumper H1-5 IN)

Time Delay

Warning Set Points

Alarm Set Points

Alarm Relay Latching

Optional Analogue Output

1 4

Yes None

1 + 3 digits 1 + 3 digits

Solid ON /

Variable,

(Jumper H1-6)

YES

(Jumper H1-3)

5 min. ON/OFF

OR

0-10 min., Pots

(H1-5 OUT)

Pot (H1-7 IN)

OR

35% FS

(H1-7 OUT)

Pot (H1-8 IN)

OR

50% FS

(H1-8 OUT)

YES

(Jumper H1-9)

4-20mA

(Hi-Select)

4 CHANNEL

Solid ON /

Variable,

(Jumper H1-6)

YES

(Jumper H1-3)

5 min. ON/OFF

(Jumper H1-5 IN)

OR

0-10 min., Pots

(H1-5 OUT)

Pot (H1-7 IN)

OR

35% FS

(H1-7 OUT)

Pot (H1-8 IN)

OR

50% FS

(H1-8 OUT)

YES

(Jumper H1-9)

4-20mA

(Hi-Select)

1.0

Section 2

ZGARD C Controllers
Installation Guidelines

The performance of ZGARD C Controllers is dependent on the appropriate employment of the
associated remote gas sensors. The remote gas sensors should be strategically placed
closest to the areas where the target gases or vapors might occur in the atmosphere. Follow
the recommended guidelines listed below.

Mounting:

• Do not mount the controller to structures subject to vibration and shock, such as piping and piping
supports.

• Do not locate the controller near excessive heat source or in wet and damp locations.

• For proper cooling, allow at least five inches of clearance around all surfaces except for the mounting

surface. Also consider mounting the controller so it can be easily accessed for service and routine
testing.

• Make sure the controller is not blocked; otherwise front panel lights and controls will be obscured from
view.

• The controller has four mounting lugs; securely mount the instrument to a wall or support using

Wiring Connections:

Before putting a ZGARD C controller into operation, determine the capacity, designation and number of remote
gas sensors, and configure the controller according to the required application. Also refer to the ZGARD C
controllers Installation Outline drawings located in the back of this manual, which provides important information
regarding;

appropriate hardware.

• Operating power.

• Number and type of remote sensors.

• Required conductors and wire size.

• Relay wiring connection.

• 4-20mA Output wiring connection.

CAUTION

1. When wiring the controller, disconnect the main power to prevent bodily harm.

2. Do not use the controller power when connecting any external devices to the relay contacts.

3. Use shielded cable for wiring installation. Do not install low voltage signal cable in the same conduit as

the controller’s operating power and or relay wiring.

4. Do not exceed the contact ratings marked on the relays.

5. Make sure that each sensor is given a unique address (Jumper selected), or the ZGARD C controller

may not be able to communicate appropriately.

6. When connecting the remote sensors, make sure that all wiring is correct for the power and signal

leads. Ensure the RS485 bus wiring is not interchanged, or permanent damage to the sensor may

result.

7. Perform all wiring and conduit installation in accordance to the National Electrical Code.

8. The fuse at the input is a SloBlo type fuse and REPLACE FUSE ONLY WITH A FUSE WITH THE

SAME RATING.

Failure to follow the above cautions can result in injury or property damage.

2.0

Section 3

ZGARD C 1-Channel Controller

General Information

OPERATING SPECIFICATIONS
Remote Sensor Input 1 only, 4-20mA analogue, 2 or 3wire OR RS485 digital data bus, 4-wire connection
Remote Sensor Power
Network Capacity
Power Requirements
(Optional)
Temperature
LED Readout
Status LED Indicators
Audible Alarm
Pushbutton
Alarm & Warning Set points
Sensor Fail Set point
Time Delays Fixed 5 minutes ON delay for Alarm and 5 minutes OFF delay for Warning or manually

Relay Outputs
Relay Action

Relay Contacts Rating
(Optional) Signal Output

Enclosure
(Optional)
Dimensions
Weight
Certification

Sensor Input: The ZGARD C 1-Channel controller

accepts 1 remote gas sensor. The MSA ZGARD S or
GS, 4-20mA 2 or 3-wire analogue or RS485 type
sensor. The RS485 serial communication sensors are
automatically recognized by the controller and establish
the sensor range and gas code type.

Readout: LED display exhibits the corresponding sensor
gas concentration level.

Warning and Alarm Set Points: The Warning and Alarm
threshold levels are independently adjustable on the
controller and can be set to any value between 0 and
100% Full-Scale (FS).

Delay Function: There are two user jumper selected
methods for setting the ZGARD C 1-Channel controller
warning and alarm delays. The first uses pre­programmed, fixed delays of 5 minutes OFF delay for
warning and 5 minutes ON delay for alarm. The second
allows adjusting of the delays from 0 to 10 minutes using
potentiometers.

Warning and Alarm Scheme: During a Warning event,
the Warning (Amber) LED will turn on and the warning
relay will be activated. No audible alarm is set off at this
time. Once a warning occurrence has been abated, the
associated warning LED will turn off and the warning
relay will be deactivated. If the 5 minute delay feature is
selected, then this action takes place after a 5 minute

24Vdc at 100mA / Input
1 Remote Gas Sensor
Standard 110Vac, 50/60 Hz ± 10% at 0.15 Amps
220Vac, 50/60 Hz ± 10% at 0.10 Amps; 24Vdc ± 10% at 0.5 Amps
Operating: -10° to 40°C (14° to 104°F); Storage: -20° to 50°C (-4° to 122°F)
1 + 3 Digit LED display exhibits the channel number and gas level, at 2 second intervals
Power, Warning, Alarm and Sensor OK
Electronic device, 93 dB @ 0.3 meters with variable sound selection
Alarm reset and Silence function
Factory set at 35% and 50% Full-Scale, unless otherwise specified (Field Adjustable)
Non-adjustable

adjusted from 0 to10 minutes
Warning Relay, Alarm Relay and Sensor Fail Relay: Form C - SPDT
Alarm Relay Latching or Non-Latching, jumper selected

10 Amps 1/8 H.P., 125Vac, 5 Amps, 30Vdc, 6 Amps 1/8 H.P., 277Vac
4-20mA analogue output

Metal NEMA 1
Fiberglass NEMA 4X design

11.5” H (292 mm) x 10” W (254 mm) x 3.75” D (95 mm)

4.5kg (10 lbs.)
ENTELA (to CSA Standards)

delay period. During an Alarm event, the associated
Alarm (Red) LED will turn on and the alarm relay will be
activated. If the 5 minute delay feature is selected and the
alarm event has prolonged for a period of 5 minutes, then
the alarm relay will be activated and the audible device
will sound. Pressing the reset button on the front panel
will silence the audible device. Once the alarm
occurrence has been abated, the audible device will
silence (if not silenced already by reset button) and the
alarm relay will be deactivated. If any other active
channels reach the alarm state, the audible device will
sound with every new alarm event. Once all of the active
channels have been cleared of alarm events, the audible
device will silence (if not silenced already by reset button)
and the alarm relay will be deactivated.

Sensor Fail: If an analog sensor is used and the input is
between 1mA and 3.5mA, the Sensor OK LED will turn
off and the Sensor Fail Relay will be activated. Any
analog input below 1.0mA causes the controller to ignore
that analog input and treat that sensor as an RS485 type
sensor. If there is a lose of communication between the
controller and the remote gas sensor residing on the
RS485 network, the Sensor Fail Relay will be activated
and the Sensor OK LED will turn off.

Optional 4-20mA Output: The analogue output
continuously represents the signal generated by the
remote sensor output.

3.0

Section 3

ZGARD C 1-Channel Controller
Installation and Setup

H2

RANGE A H2-2 H2-1 RANGE B H2-2 H2-1

1

2

999 OUT OUT 500 OUT OUT
250 OUT IN 200 OUT IN
100 IN OUT 75 IN OUT

10.0 IN IN 50 IN IN

H1 PARAMETER SETUP

1

2

3

4

5

6

7

8

9

RELAY NORMALLY EN/DE (IN/ OUT)
DISPLAY RANGE B/A (IN/ OUT)
DELAY 5MIN. / POT (IN/ OUT)
HORN SOLID / VAR (IN / OUT)
WARNING POT / 35% (IN / OUT)
ALARM POT / 50% (IN / OUT)
ALARM LATCH (IN)

Display Mode:

The ZGARD C controller can accept a 4-20mA or RS485 input signal depending on the type of remote
gas sensor employed. If the incoming signal is a 4-20mA analog type, then the controller must be
configured to reflect the actual operating range of the incumbent remote gas sensors.

There are two display mode options, A and B and is selected by placing Jumper H2 in the required
position. If jumper H1-4 is OUT, Range A is selected. If jumper H1-4 is IN, then Range B is selected.
After the display mode is chosen the operating range must be selected. This option is chosen using
Jumper H2 with various jumper positions for the different display operating ranges.

On the main circuit of every ZGARD C
Controller is a series of user configurable
components for setting, adjustment and
selecting the required functionality and
operation of the instrument. Refer to the

associated controller, Installation Outline
Drawing, 106956 for further details.

3.1

Setting-up Relay Functions:

When jumper H1-3 is not inserted (OUT), all relays are normally de-energized when inactive and
energized when activated. If jumper H1-3 is inserted (IN), then all relays are normally energized when
inactive and de-energized when activated.

Setting-up the Warning & Alarm Delays:

There are two methods for setting the warning and alarm delays. The first uses pre-programmed,
fixed delays of 5 minutes OFF delay for warning and 5 minutes ON delay for alarm. To select the fixed
delay, jumper H1-5 must be inserted.

The second allows adjusting of the delays from 0 to 10 minutes via two potentiometers (labeled:
Warning Delay, Alarm Delay). To select the adjustable delay, jumper H1-5 is NOT inserted. Removing
the jumper activates the associated potentiometer and test points (TP3 for warning delay and TP4 for
alarm delay). The test points show a voltage of 0-5Vdc for a delay of 0 - 10 minutes.

TP = Delay (minutes)/10 x 5Vdc

Example: To set up a Warning delay of 4 minutes and an Alarm delay of 6 minutes,

Warning Delay TP3 and TPCOM should read: Warning Delay (4/10) x 5 = 2.0Vdc

Alarm delay TP4 and TPCOM should read: Alarm Delay (6/10) x 5 = 3.0Vdc

H1 PARAMETER SETUP

1

2

3

4

DISPLAY RANGE B/A (IN/ OUT)

5

DELAY 5MIN. / POT (IN/ OUT)

6

HORN SOLID / VAR (IN / OUT)

7

WARNING POT / 35% (IN / OUT)

8

ALARM POT / 50% (IN / OUT)

9

ALARM LATCH (IN)

ZGARD C 1-Channel Controller

RELAY NORMALLY EN/DE (IN/ OUT)

Section 3

Installation and Setup

3.2

Section 3

ZGARD C 1-Channel Controller
Installation and Setup

H1 PARAMETER SETUP

Audible Alarm Device Setting:

There are two audible alarm modes. The first is a Solid-ON mode that sounds the audible alarm
continuously while the ZGARD C controller is in an alarm state. The second is a Variable-ON mode that
sounds the audible alarm in an eight second interval pulsed fashion. The time between pulses is fixed,
but the on-time of the audible alarm is determined by the amount that the alarming sensor is exceeding
the alarm set point. For example, if the set point is at 50% and an alarm comes in at 55%, the audible
alarm would give short beeps every eight seconds. As the alarm level increases from 55% to 100%, the
beeps become longer in duration until a solid tone appears at 100%.

To select the Solid-ON audible alarm mode, jumper H1-6 must be inserted. To select the variable-ON
audible alarm mode, jumper H1-6 must be removed. In both modes, pressing the reset button will
silence the audible alarm, but will not have any effect on the alarm LED on the front panel or the alarm
relay.

Warning and Alarm Set-Points:

There are two methods for setting the warning and alarm set points. The first uses pre-programmed,
fixed set points of 35% for warning and 50% for alarm.

The second allows for adjusting the set points anywhere from 0% to 100% via two potentiometers
(labeled: WARNING, ALARM). To select the fixed set points, jumpers H1-7 (warning) and/or H1-8
(alarm) must NOT be inserted. Inserting a jumper activates the associated potentiometer and test
point (TP1 for warning and TP2 for alarm). The test points show a voltage of 0 - 5Vdc for a set point of
0 - 100%.

TP = Set point (% full-scale)/100 x 5Vdc.

Example: To set up a Warning threshold of 25% FS and an Alarm threshold of 60% FS.

Warning Set-Point TP1 and TPCOM should read: Warning (25/100) x 5 = 1.25Vdc

Alarm Set-Point TP2 and TPCOM should read: Alarm (60/100) x 5 = 3.0Vdc

1

2

3

4

5

6

7

8

9

RELAY NORMALLY EN/DE (IN/ OUT)
DISPLAY RANGE B/A (IN/ OUT)
DELAY 5MIN. / POT (IN/ OUT)
HORN SOLID / VAR (IN / OUT)
WARNING POT / 35% (IN / OUT)
ALARM POT / 50% (IN / OUT)
ALARM LATCH (IN)

3.3

ZGARD C 1-Channel Controller

Installation and Setup

H1 PARAMETER SETUP

1

2

3

4

5

6

7

8

9

RELAY NORMALLY EN/DE (IN/ OUT)
DISPLAY RANGE B/A (IN/ OUT)
DELAY 5MIN. / POT (IN/ OUT)
HORN SOLID / VAR (IN / OUT)
WARNING POT / 35% (IN / OUT)
ALARM POT / 50% (IN / OUT)
ALARM LATCH (IN)

Alarm Relay Latch Set-up:

Normally all relays return to their inactive state once an Alarm event has cleared. The alarm relay can
be made to latch in the activated position even after all alarms have cleared. Inserting jumper H1-9 (IN)
will lock in the alarm relay so it will remain latched after all alarms clear until the reset button is pressed.
Note that the Alarm LED on the front panel will not follow this action.

Analog Output Adjustment:

The analog output (4-20mA) is factory calibrated, and should not require adjustment. It does not drift
because it is digitally controlled by the microprocessor. If adjustments are required, a ZERO and SPAN
potentiometer can be used to perform these.

To adjust the output to 4-20mA for 0-100% input (factory setting) when using a 4-20mA type sensor,
apply a 0% (4mA) signal to the input and adjust the ZERO potentiometer until the output reads 4mA.
Then apply a 100% (20mA) signal to the input and adjust the SPAN potentiometer until the output
reads 20mA.

To adjust the output to 4-20mA for 0-100% input (factory setting) when using RS485 type sensors, a 0%
and 100% input can be obtained by making sure the sensor is not exposed to any gas or ideally by
disconnecting the sensor (the Sensor Fail will then activate - ignore it) for a 0% signal, and by inserting
the 100% jumper on the back of the sensor board for a 100% signal.

Section 3

3.4

Section 4

ZGARD C 4-Channel Controller
General Information

OPERATING SPECIFICATIONS
Remote Sensor Inputs Up to 4, 4-20mA analogue, 2 or 3wire OR RS485 digital data bus, 4-wire connection
Remote Sensor Power
Network Capacity
Power Requirements
(Optional)
Temperature
LED Readout
Status LED Indicators
Audible Alarm
Pushbutton
Alarm & Warning Set points
Sensor Fail Set point
Time Delays Fixed 5 minutes ON delay for Alarm and 5 minutes OFF delay for Warning or manually

Relay Outputs
Relay Action

Relay Contacts Rating
(Optional) Signal Output

Enclosure
(Optional)
Dimensions
Weight
Certification

Sensor Inputs: The ZGARD C 4-Channel controller

accepts up to 4 remote gas sensors. The MSA ZGARD
S or GS, 4-20mA 2 or 3-wire analogue or RS485 type
sensors. The RS485 serial communication sensors are
automatically recognized by the controller and establish
the sensor range and gas code type.

Readout: LED display exhibits the active channel
number and the corresponding sensor gas concentration
level. The display scans through all of the active channels
at 2-second intervals.

Warning and Alarm Set Points: The Warning and Alarm
threshold levels are independently adjustable on the
controller and can be set to any value between 0 and
100% Full-Scale (FS).

Delay Function: There are two user jumper selected
methods for setting the ZGARD C 4-Channel controller
warning and alarm delays. The first uses pre­programmed, fixed delays of 5 minutes OFF delay for
warning and 5 minutes ON delay for alarm. The second
allows adjusting of the delays from 0 to 10 minutes using
potentiometers.

Warning and Alarm Scheme: During a Warning event,
the associated Warning (Amber) LED will turn on and the
warning relay will be activated. No audible alarm is set off
at this time. Once a warning occurrence has been
abated, the associated warning LED will turn off and the
warning relay will be deactivated. If the 5 minute delay

24Vdc at 100mA / Input
4 Remote Gas Sensors
Standard 110Vac, 50/60 Hz ± 10% at 0.5 Amps
220Vac, 50/60 Hz ± 10% at 0.25 Amps; 24Vdc ± 10% at 1.0 Amps
Operating: -10° to 40°C (14° to 104°F); Storage: -20° to 50°C (-4° to 122°F)
1 + 3 Digit LED display exhibits the channel number and gas level, at 2 second intervals
Discrete Warning, Alarm and Sensor OK for each channel
Electronic device, 93 dB @ 0.3 meters
Alarm reset and Silence function
Factory set at 35% and 50% Full-Scale, unless otherwise specified (Field Adjustable)
Non-adjustable

adjusted from 0 to10 minutes
4-Warning Relays and a common Alarm Relay and a Sensor Fail Relay: Form C - SPDT
Alarm Relay Latching or Non-Latching, jumper selected

10 Amps 1/8 H.P., 125Vac, 5 Amps, 30Vdc, 6 Amps 1/8 H.P., 277Vac
4-20mA, high select analogue output

Metal NEMA 1
Fiberglass NEMA 4X design
15” H (381 mm) x 12” W (305 mm) x 3.75” D (95 mm)

6.8kg (15 lbs.)
ENTELA (to CSA Standards)

feature is selected, then this action takes place after a 5
minute delay period.

During an Alarm event, the associated Alarm (Red) LED
will turn on and the alarm relay will be activated. If the 5
minute delay feature is selected and the alarm event has
prolonged for a period of 5 minutes, then the alarm relay
will be activated and the audible device will sound.
Pressing the reset button on the front panel will silence
the audible device. Once the alarm occurrence has been
abated, the audible device will silence (if not silenced
already by reset button) and the alarm relay will be
deactivated. If any other active channels reach the alarm
state, the audible device will sound with every new alarm
event. Once all of the active channels have been cleared
of alarm events, the audible device will silence (if not
silenced already by reset button) and the alarm relay will
be deactivated.

Sensor Fail: If an analog sensor is used and the input is
between 1mA and 3.5mA, the Sensor OK LED will turn
off and the Sensor Fail Relay will be activated. Any
analog input below 1mA causes the controller to ignore
that analog input and treat that sensor as an RS485 type
sensor. If there is a lose of communication between the
controller and the remote gas sensor residing on the
RS485 network, the Sensor Fail Relay will be activated
and the Sensor OK LED will turn off.

Optional 4-20mA Output: The analogue output
continuously represents the highest signal generated by
all of the active channel inputs.

4.0

Section 4

ZGARD C 4-Channel Controller

Installation and Setup

H2

RANGE A H2-2 H2-1 RANGE B H2-2 H2-1

1

2

999 OUT OUT 500 OUT OUT
100 OUT IN 200 OUT IN

10.0 IN OUT 75 IN OUT

* 10.0/100 IN IN 50 IN IN

H1 PARAMETER SETUP

1

2

3

4

5

6

7

8

9

Number of Active Points

1

1 + (0 -3 )

2

RELAY NORMALLY EN/DE (IN/ OUT)
DISPLAY RANGE B/A (IN/ OUT)
DELAY 5MIN. / POT (IN/ OUT)
HORN SOLID / VAR (IN / OUT)
WARNING POT / 35% (IN / OUT)
ALARM POT / 50% (IN / OUT)
ALARM LATCH (IN)

On the main circuit of every ZGARD C
Controller is a series of user configurable
components for setting, adjustment and
selecting the required functionality and
operation of the instrument. Refer to the

associated controller, Installation
Outline Drawing, 106957 for further
details.

Display Mode:

The ZGARD C 4-Channel controller can accept up to 4, 4-20mA or RS485 input signals depending on
the type of remote gas sensors employed. If the incoming signals are 4-20mA analog type, then the
controller must be configured to reflect the actual operating range of the incumbent remote gas
sensors.

There are two display mode options, A and B and is selected by placing Jumper H2 in the required
position. If jumper H1-4 is OUT, Range A is selected. If jumper H1-4 is IN, then Range B is selected.
After the display mode is chosen the operating range must be selected. This option is chosen using
Jumper H2 with various jumper positions for the different display operating ranges.

* Range A 10.0/100 is a special Display Range that displays the first two channels (1 & 2) as 0-

10.0ppm and the second two channels (3 & 4) as 0-100ppm. This is useful for Carbon Monoxide (CO) /
Nitrogen Dioxide (NO2) applications.

Remote RS485 Digital Sensor Inputs:

The number of active remote sensors is set by arranging the user selection jumpers shown on H1-1 and
H1-2. Care must be taken to represent the number of remote sensors connected for each application.
Insert the jumpers such that the decimal equivalent of the binary code on H1-1 and H1-2 plus one
equals the number of active sensors to be scanned.

Connect a 4-conductor serial bus electrical cable between the devices. The connection terminal labeled
Data 1 and Data 2 are for communication while the +24Vdc and COM are for power, supplied by the
ZGARD C controller. Refer to the associated controller, Installation Outline Drawing 106957 for

further details.

4.1

Section 4

ZGARD C 4-Channel Controller
Installation and Setup

Setting-up Relay Functions:

When jumper H1-3 is not inserted (OUT), all relays are normally de-energized when inactive and
energized when activated. If jumper H1-3 is inserted (IN), then all relays are normally energized when
inactive and de-energized when activated.

Setting-up the Warning & Alarm Delays:

There are two methods for setting the warning and alarm delays. The first uses pre-programmed,
fixed delays of 5 minutes OFF delay for warning and 5 minutes ON delay for alarm. To select the fixed
delay, jumper H1-5 must be inserted.

The second allows adjusting of the delays from 0 to 10 minutes via two potentiometers (labeled:
Warning Delay, Alarm Delay). To select the adjustable delay, jumper H1-5 is NOT inserted. Removing
the jumper activates the associated potentiometer and test points (TP3 for warning delay and TP4 for
alarm delay). The test points show a voltage of 0-5Vdc for a delay of 0 - 10 minutes.

TP = Delay (minutes)/10 x 5Vdc

Example: To set up a Warning delay of 4 minutes and an Alarm delay of 6 minutes,

Warning Delay TP3 and TPCOM should read: Warning Delay (4/10) x 5 = 2.0Vdc

Alarm delay TP4 and TPCOM should read: Alarm Delay (6/10) x 5 = 3.0Vdc

H1 PARAMETER SETUP

1

2

3

4

5

6

7

8

9

Number of Active Points

1

1 + (0 -3 )

2

RELAY NORMALLY EN/DE (IN/ OUT)
DISPLAY RANGE B/A (IN/ OUT)
DELAY 5MIN. / POT (IN/ OUT)
HORN SOLID / VAR (IN / OUT)
WARNING POT / 35% (IN / OUT)
ALARM POT / 50% (IN / OUT)
ALARM LATCH (IN)

4.2

ZGARD C 4-Channel Controller

Installation and Setup

H1 PARAMETER SETUP

1

2

3

4

5

6

7

8

9

Number of Active Points

1

1 + (0 -3 )

2

RELAY NORMALLY EN/DE (IN/ OUT)
DISPLAY RANGE B/A (IN/ OUT)
DELAY 5MIN. / POT (IN/ OUT)
HORN SOLID / VAR (IN / OUT)
WARNING POT / 35% (IN / OUT)
ALARM POT / 50% (IN / OUT)
ALARM LATCH (IN)

Audible Alarm Device Setting:

There are two audible alarm modes. The first is a Solid-ON mode that sounds the audible alarm
continuously while the ZGARD C controller is in an alarm state. The second is a Variable-ON mode that
sounds the audible alarm in an eight second interval pulsed fashion. The time between pulses is fixed,
but the on-time of the audible alarm is determined by the amount that the alarming sensor is exceeding
the alarm set point. For example, if the set point is at 50% and an alarm comes in at 55%, the audible
alarm would give short beeps every eight seconds. As the alarm level increases from 55% to 100%, the
beeps become longer in duration until a solid tone appears at 100%.

To select the Solid-ON audible alarm mode, jumper H1-6 must be inserted. To select the variable-ON
audible alarm mode, jumper H1-6 must be removed. In both modes, pressing the reset button will
silence the audible alarm, but will not have any effect on the alarm LED on the front panel or the alarm
relay.

Warning and Alarm Set-Points:

There are two methods for setting the warning and alarm set points. The first uses pre-programmed,
fixed set points of 35% for warning and 50% for alarm.

The second allows for adjusting the set points anywhere from 0% to 100% via two potentiometers
(labeled: WARNING, ALARM). To select the fixed set points, jumpers H1-7 (warning) and/or H1-8
(alarm) must NOT be inserted. Inserting a jumper activates the associated potentiometer and test
point (TP1 for warning and TP2 for alarm). The test points show a voltage of 0 - 5Vdc for a set point of
0 - 100%.

TP = Set point (% full-scale)/100 x 5Vdc.

Example: To set up a Warning threshold of 25% FS and an Alarm threshold of 60% FS.

Warning Set-Point TP1 and TPCOM should read: Warning (25/100) x 5 = 1.25Vdc

Alarm Set-Point TP2 and TPCOM should read: Alarm (60/100) x 5 = 3.0Vdc

Section 4

4.3

Section 4

ZGARD C 4-Channel Controller
Installation and Setup

H1 PARAMETER SETUP

Alarm Relay Latch Set-up:

Normally all relays return to their inactive state once an Alarm event has cleared. The alarm relay can
be made to latch in the activated position even after all alarms have cleared. Inserting jumper H1-9 (IN)
will lock in the alarm relay so it will remain latched after all alarms clear until the reset button is pressed.
Note that the Alarm LED on the front panel will not follow this action.

Analog Output Adjustment:

The analog output (4-20mA) is factory calibrated, and should not require adjustment. It does not drift
because it is digitally controlled by the microprocessor. If adjustments are required, a ZERO and SPAN
potentiometer can be used to perform these.

To adjust the output to 4-20mA for 0-100% input (factory setting) when using a 4-20mA type sensor,
apply a 0% (4mA) signal to one of the input and adjust the ZERO potentiometer until the output reads
4mA. Then apply a 100% (20mA) signal to input and adjust the SPAN potentiometer until the output
reads 20mA.

To adjust the output to 4-20mA for 0-100% input (factory setting) when using RS485 type sensors, a 0%
and 100% input can be obtained by making sure the sensor is not exposed to any gas or ideally by
disconnecting the sensor (the Sensor Fail will then activate - ignore it) for a 0% signal, and by inserting
the 100% jumper on the back of the sensor board for a 100% signal.

1

2

3

4

5

6

7

8

9

Number of Active Points

1

1 + (0 -3 )

2

RELAY NORMALLY EN/DE (IN/ OUT)
DISPLAY RANGE B/A (IN/ OUT)
DELAY 5MIN. / POT (IN/ OUT)
HORN SOLID / VAR (IN / OUT)
WARNING POT / 35% (IN / OUT)
ALARM POT / 50% (IN / OUT)
ALARM LATCH (IN)

4.4

Section 5

ZGARD C Controllers

Start-Up Procedure

When wiring, checking or working within a ZGARD C Controller, always disconnect the main
power to prevent bodily harm.

1. Loosen the locking screws on front of the controller and open the door.

2. Locate the power switch on main circuit board inside controller enclosure.

3. Check all wiring connections are correct and secure.

4. Confirm that the selection jumpers are appropriately inserted to reflect binary code for the number of

remote sensors associated with the corresponding controller.

5. Confirm that each controller’s active 4-20mA remote sensor(s) are appropriately wired to the appropriate

analog input terminals. OR Confirm that each controller’s active RS485 digital remote sensor(s) are

appropriately assigned a unique binary address code. Refer to the appropriate gas sensor manual

for further details.

6. Power up the controller and observe the behavior of the following indicators;

Green LED (POWER) Indicator on front panel should be ON.

(On the 1-Channel Controllers only)

Green LED (Sensor OK) Indicator(s) on front panel should be ON.

Amber LED (WARNING) Indicator(s) on front panel should be OFF.

Red LED (ALARM) Indicator(s) on front panel should be OFF.

During initial power up of the controller, the local audible alarm may be activated, press RESET button
to silence.

7. Allow the associated remote gas sensors to stabilize. Refer to the appropriate gas sensor manual for
further details.

Depending on the controller’s warning, alarm and delay settings, the display status and the relay action
of the controller may vary. Refer to the installation sections of the associated ZGARD C Controller.

8. Confirm the functionality of the controller and that is operating according to the designed or pre-set
configuration settings.

9. Apply a representative sample (at least 60% of the operating range) of the target gas to each of the
associated remote gas sensors. This simple test should drive the gas sensors upscale and simulate a
warning and or an alarm condition on the controller. Refer to the appropriate gas sensor manual for
further details.

During this procedure, the audible device may be activated, press RESET button to silence.

The warning and alarm indicators and the corresponding relays may be activated.

Depending on the controller’s warning and alarm set-points and delay feature settings, the Warning and

Alarm relays may be activated.

Any remote equipment, which may be connected to the controller relay contacts, should now be
activated.

10. Remove any test equipment from the sensor and controller.

11. Secure the locking screws on the front door of the ZGARD C Controller.

12. Secure the locking screws on cover or front door of the associated remote gas sensors.

9 The initial function test of the ZGARD C Controller is now completed.

5.0

Section 6

ZGARD C Controllers
Parts List

Item Part Number

1-Channel Controller 10097989

1-Channel Display 10090652

1-Channel Ribbon Cable Assembly 10090653

Item Part Number

4-Channel Controller 10097990

4-Channel Display 10097928

4-Channel Ribbon Cable Assembly 10097988

* When ordering replacement parts, please state the MSA P/N and S/N of unit.

WARNING

Use only genuine MSA replacement parts when performing any maintenance on the ZGARD C
Controllers. Failure to do so may seriously impair instrument performance. Repair or alteration of the
ZGARD C controllers, beyond the scope of these maintenance instructions or by anyone other than
authorized MSA service personnel, could cause the product to fail to perform as designed, and
persons who rely on this product for their safety could sustain serious personal injury or death.

Disconnect all power source(s) to the ZGARD C Controllers before removing or changing any
components.

6.0