8A. ZERO ADJUSTMENT
7: OPERATION OVERVIEW
LED Operation
SHIELD WIRE WARNING:
Connect the shield of
Modbus wires to the earth ground of the central
control system (e.g., chassis, ground bus bar, etc.).
Normal mode,
no alarm
Low gas alarm
High gas alarm
Fault
Under range
(perform
zero adjust)
Over range
(remove gas)
Offline (not in
calibration
mode)
Normal/Alarm/Fault/
Special States
Waiting to start
calibration mode
During calibration
Zero calibration
error
Zero Cal Mode
Waiting to start
calibration mode
During calibration
Span calibration
error
Span Cal Mode
Magnetic Switch Functions
Buzzer Operation
No alarm
Low gas alarm
Muted alarm
High gas alarm
Fault (continuous)
8: GENERAL CALIBRATION PROCEDURE
1.
The detector must not be in alarm or fault condition. (One
exception is a negative gas concentration fault -- which requires
a zero calibration.)
2.
Calibration gas must be in balance of air,
not
Nitrogen (N
2
).
3.
Attach the pressure regulator to the calibration gas cylinder.
4. Fit calibration adapter over sensor module, aligning its 3
notches with the sensor alignment ribs.
5. The gas flow should be approximately 0.3 to 1.0 L/min.
6.
If operation is intended to be at higher altitudes, the factory
calibration will result in a reading lower than the reading at sea
level (reduced partial pressure). A new span adjustment is
recommended if the altitude or the ambient pressure is
changed. The factory calibration is set to sea level.
7. Connect the tubing to the barbed fitting.
8. Always perform a zero adjustment before a span adjustment.
8B. SPAN ADJUSTMENT
WARNING:
Ambient air can be used to zero the
sensor instead of synthetic air only if the area is
known to be free of the target gas or any gas to which
the sensor may be cross-sensitive. In this case, no
cylinder or calibration adapter is needed for the zero
adjustment.
9. Tap and hold ( • ) for >5 seconds. The LED will blink
green-green-red when the detector is ready.
10. Apply synthetic air (or use ambient air per warning above).
11. Tap ( • ) within 30 seconds to confirm start of calibration.
Otherwise the detector will time-out and return to normal
operation.
12. As the process progresses, the LED will blink green-red,
green-red-red, green-red-red-red, etc.
• To abort calibration, tap and hold ( • ) for >5 seconds,
turn off gas flow and remove the calibration adapter.
The detector will return to normal operation.
• If calibration is successful (green LED), skip to step 13.
• If calibration is unsuccessful (orange LED blinks @ 2 Hz),
then tap ( • ) to discard the calibration attempt, and see
User Manual (P/N 6203-9000) for troubleshooting.
13. Turn off gas flow from synthetic air.
14. Replace synthetic air tank with calibration gas tank in
preparation for span adjustment (if required).
9. BUMP TEST
Negative gas
fault (perform
zero adjust)
Recovery from
span calibration
2.0 = 2.0 Hz
2 cycles/second
FAST flash/chirp
0.5 = 0.5 Hz
0.5 cycles/second
SLOW flash/chirp
LED Colors
6: INSTALLATION (CONTINUED)
Warmup mode
(≈ 6 minutes)
15.
Tap and hold
( •• ) for >5 seconds. The LED will blink
green-green-orange when the detector is ready.
16. Apply span gas in the concentration listed on the cal gas
concentration label (beneath the detector’s cover plate).
This may require the temporary removal of the bezel and
cover plate to see the label.
17. Tap ( •• )
within 30 seconds to confirm initiation of
the calibration. Otherwise the detector will time-out and
return to normal operation.
18. As the calibration process progresses, the LED will blink
green-orange, green-orange-orange,
green-orange-orange-orange, etc.
• To abort calibration, tap and hold ( •• ) for >5 seconds
,
turn off gas flow and remove the calibration adapter.
The detector will return to normal operation after
6 minutes of recovery time.
• If calibration is successful, the LED will blink
green-orange-red indicating ‘offline’). Turn off gas flow
and remove the calibration adapter. Afte
r 6 minutes
the detector will return to normal operation.
• If calibration is unsuccessful (orange LED blinks @ 2 Hz),
then tap ( •• ) to discard the calibration attempt, and
see User Manual (P/N 6203-9000) for troubleshooting.
Turn off gas flow and remove the calibration adapter.
Afte
r 6 minutes the detector will return to normal
operation.
1.
Inform building personnel of test so that certain alarms
may be inhibited (e.g., shutdown valves, notification of
authorities, etc.).
2.
Connect adapter and target gas according to instructions in
General Calibration Procedure.
3.
Apply a sufficiently high concentration of target gas to
trigger alarms, but not pure refrigerant or hydrocarbons
(e.g., do not use a butane lighter).
4.
Once the alarm thresholds are exceeded, all designated
gas alarm relays will be activated and the digital outputs
will transmit the corresponding gas concentrations.
5.
Turn off gas flow and remove calibration adapter.
High Gas Alarm
or Fault
Rela
y #2
NC
NO
COM
Low Gas Alarm
Rela
y #1
NC
NO
COM
Example of custom faceplate
Grounding lugs
Example of UK back box
Mounting tabs
Direction arrows (×2) for
proper mounting
Sensor type/calibration and
ID/serial number labels
Test point access holes (×2)
Replaceable sensor module
Sensor alignment ribs (×3)
5 s
8A
5 s
8B
5 s
5 s
5 s
Latched
alarm
60 min
60 min
Clears one
or both
latched
alarms
Flow meter
Pressure regulator
Calibration gas
Tubing
Calibration adapter
Back view of a customized
faceplate (not included)
Sample
UK back box
(not included)
NOTE:
For specifications and recommended drill
patterns for customizing a metal UK faceplate, visit the
MVR-300 product page at www.MyBacharach.com.
NOTE:
For UK back boxes with “higher” mounting
tabs, remove the thick plastic mounting tabs from
the detector (using wire snips or nippers) and screw
on the thinner metal mounting tabs (included) to
ensure flush wall mounting of the faceplate. Be sure
to dry fit the plastic tabs before cutting them from
the detector to verfiy that they are too thick for
proper flush mounting of the faceplate to the wall.
COVER GROUNDING:
For proper cover ground-
ing, wire the ground lug of the faceplate to the
ground lug of the earth grounded back box.
If the cus
tom f
acepla
te drill pa
ttern does not acc
ommoda
te the tw
o magne
tic s
wit
ch
loc
ations, the f
acepla
te mus
t be r
emo
ved t
o use the magne
tic w
and functions.
