GB
MODELS DESCRIPTION
MPU2C
Two channel unit
MPU4C
Four channel unit
MPU6C
Six channel unit
FEATURES
- The MPU is a multi-channel microprocessor based gas
monitoring system. Each, up to a maximum of six channels, can
be individually configured to monitor different gases with up to
three alarm concentrations all with status LEDs.
Other features include:
- User configurable Alarm time delays.
- Manual/auto alarm reset for each channel
- Built-in service function and self test program
- Four alarm relays with 230 volt rated SPDT contacts
- Failsafe relay operation on power loss
- Audible alarm
- Optional battery back-up
- Low voltage output for auxiliary alarm indication.
OPERATION
After connecting each detector and applying power, the green
LED on each channel will flash as the pre-heat process
commences. After approximately 4 minutes the green LED will
be illuminated permanently and the sensor is fully operational.
Each channel has one yellow and two red warning LEDs. The
yellow LED indicates a low-level gas leak (above alarm
threshold C) whilst the two red LEDs indicate gas
concentrations above thresholds B and A.
When gas is detected above the respective alarm threshold the
appropriate LED's will flash until the appropriate time delay has
expired when it is permanently illuminated and the
corresponding relay contacts change state. As the gas
concentration subsides the LEDs and relays will return to their
normal state unless the 'manual reset' function has been
selected. The audible alarm will be initiated if it is configured
with the respective alarm threshold and can not be muted.
Technicians can however inhibit the alarm by selecting 'Service
Mode'.
AUTO/MANUAL ALARM RESET
o
DIP switch (5) n
3 on each channel's control card manages the
alarm reset function. "ON" enables Auto reset and "OFF"
enables Manual reset, via depressing "Reset/Test/Service"-
button (7).
ALARM TIME DELAY (T1)
DIP-switch (5) controls the alarm time delay for each channel.
o
o
n
1
n
2
on
on
No alarm delay
off
on
1 minute delay
on
off
10 minute delay
off
off
30 minute delay
RESET/TEST/SERVICE-BUTTON (7)
Reset/Test/Service-functions is accessible via a pushbutton on
the cover.
TEST MODE
By depressing the "Reset/Test/Service"-button (7) on any
channel for 5 seconds the test program is initiated. This
sequentially energizes each LED and relay at five second
intervals. That the test program has started is indicated by the
fact that all LEDs on chosen channel will go out.
SERVICE MODE
Depressing the "Reset/Test/Service" button (7) for 10 seconds
will inhibit all alarm functions for the chosen channel for a period
of 60 minutes. Service mode is indicated by the fact that all
LEDs on the chosen channel is flashing. Whilst in this mode a
new 60 minute inhibit period can be initiated by repeating the
process. Normal operation will be automatically resumed after
60 minutes or can be cancelled by depressing the "Reset/Test/
Service"-button briefly.
IS MPU 1306.doc
MPU2C, MPU4C, MPU6C
FAULT MODE
In the event of a detector failure (GV offset < 0,1V) or
disconnection of the interconnecting wiring a fault condition will be
indicated by loss of the green 'Active' LED, the other LEDs start to
flash and the alarm relay D is de-energised. In the event of power
failure all relays (A, B, C & D) will be de-energized. Connections
are available for an optional battery back-up to enable total
continuity of operation in the event of a power failure. A 4-hour
delay can be configured for relay D to prevent nuisance alarms.
This is activated by setting DIP switch (5) n
channel card to 'ON'. The operation of the LEDs will remain
unchanged.
INTERNAL BUZZER AND 24VDC AUXILIARY OUTPUT
The internal buzzer (1) and 24VDC output can be activated by the
DIP-switch (4) on the terminal board and can be user configured
to operate from alarm concentration A(n
Setting the DIP-switch to ON for the respective alarm level,
selects the appropriate alarm level.
The 24VDC auxiliary alarm output is always activated together
with the buzzer. However, by removing jumper Bb (3) the buzzer
can be disabled.
Note! After being powered off for prolonged periods the sensor
may take several minutes to stabilise during which time 'false'
alarms may be initiated. Such 'false' alarm shall disappear within
a few minutes.
LED A
LED B
ON
LED C
POWER
TEST TERMINAL
A
B
C
RESET/TEST
7
o
4 on the respective
o
o
o
1), B(n
2) or C(n
3).
n 1
n 2
n 3 ALARM RESET: ON=AUTO, OFF=MANUELL
n 4 FAULT DELAY: ON=4h DELAY, OFF= NO DELAY
ALARM A
ALARM B
ALARM C
(-)
+ 5VDC
GV OFFSET