Foxcroft FX-Mini User manual

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Foxcroft FX-Mini & FX-Mini-R
Single Channel
Toxic Gas Detector
Operating Manual
Document OMFXMI I102019

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Table of Contents
Page
Introduction, Gas Sensors Available 4
Warnings, Limitations 5
FX-Mini Gas Detector Illustration 6
Detector Component Description, Main Circuit Board, Default Wiring 7
Detector Component Description, Remote Reset, Power Supply, Battery Operation 8
Detector Component Description, 10A Relay Card 9
Gas Sensor, Test Button, Unpacking, Contents, Serial umber 10
Installation, Sensor Placement Guidelines 11
Installation, Mechanical & Dimensions 12
Installation, Wiring Connections 13
Startup 14
ormal Operation, Alarm Set Points and Conditions 15
ormal Operation and Alarm Conditions: Danger & Sensor Fail Alarms 16
ormal Operation and Alarm Conditions: Sensor Fail & Oxygen Sensors 17
Gas Sensors, Sensor Fail and Oxygen Sensors, General Information & Environmental Effects 17
Calibration 19
Calibration, Setting the Zero Point 20
Calibration, Full Calibration Toxic Gas Sensors 22
Oxygen Sensor Calibration 25
Ammonia Sensor Full Calibration 26
Sensor Response (Bump) Test 27
Gas Sensor Replacement, Electrochemical Cell Only 28
Gas Sensor with Transmitter Board Replacement 29
Gas Sensor Components 30
Technical Data, Specifications 31
Service Contact 33
Warranty 34

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Introduction
The Foxcroft Equipment & Service Co. Inc. FX-Mini is a compact fixed point monitoring system
designed to detect and alarm to toxic gases or low oxygen levels in ambient air.
It’s available in two styles: the self contained all-in-one FX-Mini, and the remote controller style FX-Mini-
R, in which the gas sensor is mounted in a separate local enclosure placed in the potential hazard area.
Intended as a low cost device, it includes audible and LED visual alarm notification with 10A form C
relays to signal remote monitors and to actuate external alarm devices such as a beacon, horn, or
exhaust fan. o 4-20mA output or display of concentration is included.
The detector includes two alarm set points which are non-adjustable to prevent tampering or accidental
setting to an improper and possibly unsafe level. Upon sensing a gas concentration at an alarm set
point the detector will illuminate the appropriate color coded LED indicator light, sound the integral
audible buzzer (at the danger level only) and energize the appropriate relays that have been assigned.
The electrochemical gas sensing cell generates a voltage that is converted to a 4-20mA signal by an
analog circuit board. The signal is transmitted to the detector control circuit board, which correlates the
signal to parts per million (ppm) or percentage volume of oxygen level. The gas sensor and its signal
output are not controlled, manipulated or changed by the detector software.
The FX-Mini can be supplied with any of the following gas sensors, gas alarm trip levels below are fixed
to prevent tampering, non-standard ranges and trip levels are available. Values are in PPM except
Oxygen:
Gas Sensor Standard
Range
Warning Danger
Chlorine 0-10 ppm 0.5 1.0
Sulfur Dioxide 0-10 ppm 1.0 3.0
Ammonia 0-100 ppm 35 50
Oxygen 0-25% 18% 16%
Carbon Monoxide 0-500 ppm 35 50
Chlorine Dioxide 0-1 ppm 0.1 0.3
Hydrogen Sulfide 0-10 ppm
1.0
3.0
Ozone 0-2 ppm
0.05
0.1
itric Oxide 0-50 ppm
15
25
itrogen Dioxide 0-10 ppm
1.0
3.0
Hydrogen Cyanide 0-10 ppm
1.0
3.0
Hydrogen Chloride 0-10 ppm
0.7
2.0

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Warnings, Limitations
WARNING: NEVER attempt to calibrate a chlorine gas sensor with bleach, pool chlorinating
chemicals, or by prod cing chlorine gas with a mixt re of bleach and an acid. Any sensor
adj stment made with s ch gases or f mes, or witho t the proper known concentration of gas
will ca se the sensor to not alarm at all or to alarm at incorrect and nsafe levels. This can
create a life threatening sit ation in which the detector may not alarm d ring a chlorine gas
leak.
Warning
If the alarm buzzer sounds a loud pulsating sound and you are not testing the gas detector, it has
sensed a gas leak. The alarm buzzer is warning of a possibly serious situation and it requires your
immediate attention.
Warning
All f nctions of this gas detector m st be checked and verified on a reg lar basis.
The ability for the gas sensor to sense toxic gas or low oxygen levels must be verified on a regular
basis. It is recommended that the gas sensor be tested by means of a certified gas standard at least
once every six months.
Warning
If the FX-Mini is altered in any way the warranty will be voided.
Example; drilling additional holes in the enclosure to mount conduits, changing operating range of the
gas sensor and altering the gas alarm trip points.
Warning
Never disconnect an electrically powered gas detector to stop n isance alarms. The source of
the problem must be corrected.
FX-Mini Gas Detectors are not foolproof. Like all other electronic devices, the FX-Mini Gas Detectors
have limitations. Detectors cannot be expected to sense a dangerous toxic gas leak or low oxygen
levels if the cavity is blocked by debris or the detector is tampered with by personnel.
The FX-Mini has a limited life. This equipment contains many parts. Just as with any other device any
one of these parts could fail at any time. Therefore, you must test your detector on a regular basis. Be
sure to have it repaired or replaced when it fails to test properly. In no case should the detector be used
for more than 10 years. All functions of this detector must be checked and verified on a regular basis.

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FX-Mini Gas Detector Illustration
All-in-One Option
1. Main Circuit board. 2. AC-DC Power Supply 3. Gas Sensor.
4. 10A relay card. 5. Silence & Reset Button 6. Buzzer

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FX-Mini-R Gas Detector Illustration
Remote Controller Option
In the FX-Mini-R option the gas sensor is mounted in a separate wall mount enclosure that is placed in
the potential hazard area while the controller is mounted outside of the potential hazard area. The
devices are connected by 25-feet of 22 AWG shielded cable, up to 2,000 feet of cable is available
optionally.
Wiring connections to the gas sensor are color coded, to reconnect
simply match the colors of the wires from the sensor to those of the
two conductor cable to the controller.
FX-Mini-R sensor housings do not have the red LED indicator or
circuit test push button available on our other detectors.

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Detector Component Description
Following is a description of the system’s major components.
Main Circ it Board
The main circuit board is microprocessor based and operates on 12 VDC. It is not possible to make any
field adjustments or repairs to the circuit board. The microprocessor can be replaced with a new or
upgraded chip. The circuit board’s processor does not control the gas sensor response or signal output
in any way, it simply receives output from the sensor and energizes the alarm functions. All terminals
accept 18 to 22 AWG wire
CAUTION: the sensor printed circuit board is sensitive to Electro-Static Discharge. It can be irreparably damaged
by static electricity, causing partial or total operational failure. You must take the following precautions before
touching or making any connections to the circuit board.
Before touching the circuit board touch an earth grounded metal surface such as the detector's power supply
guard, a metal pipe or conduit to discharge any static electricity from your body, or wear an anti-static wrist strap
connected to an earth ground.
Factory Defa lt Wiring
The FX-Mini is pre-wired at the factory as follows. Field wiring to the circuit board is unnecessary
unless you are connecting a C remote reset switch. 12 & 24VDC boards are not interchangeable.
1
Power in
2
Sensor
inp t
Black to “IN”
3
Sensor inp t Red to “+12”
4
Remote reset with j mper *
5
Silence / Reset b tton
6
B zzer
7
Danger alarm relay 2
8
Sensor fail relay
9
Warning alarm relay
10
Danger alarm relay 1
1
1
Microprocessor
12
Microprocessor
“heartbeat” stat s
LED indicator
*
Do not remove j mper if a remote
reset b tton is not connected
A jumper wire is factory installed in the remote
reset terminal block; this jumper must remain
in place if a remote reset switch is not
connected.

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Detector Component Description
Terminal connections are provided for both +12VDC and +5VDC power input to the relays. 12VDC coils
are standard. The 5VDC terminals are not used as standard and should be ignored.
Remote Reset
A terminal (supplied with a factory installed jumper) is provided on the main circuit board to connect a
normally closed ( C) remote reset switch. Remove the jumper only if connecting a remote switch.
Power S pply
The detector uses a switching AC to 12VDC power supply (for all gases except those stated below) that
accepts universal voltage input of 88-264 VAC 47-63Hz. Rating: 6W max output power; output current
0.5A; short circuit, over voltage, overload protection; 2 pole USA plug, 4-ft cord, Class II power, Agency
Approvals: CE/CUL/CB/FC
The power cord plugs into a standard EMA 5-15R receptacle.
24VDC NOTE: Detectors for Ammonia, Hydrogen Cyanide and Ozone se an AC to 24VDC
power adapter that accepts niversal voltage inp t of 88-264 VAC 47-63Hz.
The board circ itry for 24VDC powered sensors is different than 12VDC powered nits; as s ch
they are not interchangeable.
WARNING: Applying 120V AC line power directly to the circ it board will destroy the detector
and void the warranty
Battery Power Operation
For battery powered operation the detector requires (1) high quality 12 volt DC battery. The detector
power consumption is about 100mA. Using a 50 amp/hour rated battery the expected battery life would
be 4-6 months.
10VDC is the minimum voltage required to energize the 10A alarm relays.
A DC volt meter may be installed to monitor battery output.

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Detector Component Description
10 Amp Relay Card
The FX-Mini gas detector includes a separate card containing (4) 10A SPDT Form C dry contact relays.
The 10A relays are unpowered when the detector is not in alarm state; they energize upon reaching an
alarm set point.
The relays are rated as follows for all gases except Ammonia, Hydrogen Cyanide and Ozone: form
C, 12VDC coil, resistive load 10A @125 VAC, 7A @ 24VDC, 7A @ 240VAC
For Ammonia, Hydrogen Cyanide and Ozone detectors: form C, 24VDC coil, resistive load 10A @125
VAC, 7A @ 24VDC, 7A @ 240VAC
WARNING: The 10A relays are not fused. Any external load connected to the relay must have a
current limiting device installed to limit current to the relay to less than 10 amps.
Relay #1 = Danger
Relay #2 = Danger
Relay #3 = Warning
Relay #4 = Sensor Fail
O = Relay red LED
O = Relay card power on LED
Relay test buttons - yellow highlight
Relays #1 & #2 by default are not adjustable in
any way; they trip at the Danger level and are
latching (they must be reset or de-energized
manually). Relay #3 is non-latching and
assigned to the Warning alarm level; relay #4 is
non-latching and assigned to Sensor Fail.
To add additional danger relays: Either of the
relays assigned to Warning or Sensor Fail can
be made to function at the Danger alarm level
by re-wiring. Take the wire from the desired
Warning or Sensor Fail relay terminal on the main circuit board and connect it to the “Coil” terminal on a
Danger relay terminal block on the main circuit board. This relay will then actuate at the Danger level
and be latching.