Inficon LDM250 User manual

Operating Manual
LDM250/LDM450/LDM650
Low Voltage
Multipoint unit
English ·

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LDM 250 450 650 Low
voltage Multipoint unit
LDM 250 450 650 Low
voltage Multipoint unit
LDM 250 450 650 Low voltage Multipoint unit............................................................................................. 3
English................................................................................................................................................................... 9

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LDM 250 450 650 Low
voltage Multipoint unit
LDM 250 450 650 Low
voltage Multipoint unit
LDM 250 450 650 Low voltage Multipoint unit
Fig. 1

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LDM 250 450 650 Low
voltage Multipoint unit
LDM 250 450 650 Low
voltage Multipoint unit
Wiring diagram

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LDM 250 450 650 Low
voltage Multipoint unit
LDM 250 450 650 Low
voltage Multipoint unit
Logical matrix
HFC, HFO, HCFC
H3 = 20 cm
X = 50 cm
Y = 20 cm
Power off
Preheat
Normal
Service mode
Fault U<0,1V
Fault U<0,1V
T<Xmin, X = delayin minutes. Letter U =
signal from sensor (Vdc).
T<Xmin.
T>Xmin.
T<Xmin.
T>Xmin.
T<Xmin.
T>Xmin.
T=<4 (h)
T=>4 (h)
LEDs (terminal board)
Power 0 X X X X X X X X X X X
Buzzer (disabled via jumper) no indication
LEDs (per channel)
Power/active 0 Flash X Flash X X X X X X 0 0
Alarm C (low level) (Vdc) 0 0 0 Flash Flash X X X X X Flash 0
Alarm B (middle level) (Vdc) 0 0 0 Flash 0 0 Flash X X X Flash X
Alarm A (high level) (Vdc) 0 0 0 Flash 0 0 0 0 Flash X Flash 0
Summary Relay output (Energised/Not energised)
Alarm C NE E E E E NE NE NE NE NE E E
Alarm B NE E E E E E E NE NE NE E E
Alarm A NE E E E E E E E E NE E E
Fault (RelayD) (no time delay) NE EEEEEEEEENE NE
Fault (RelayD) (4 hour time delay) NE EEEEEEEEEENE
Auto reset Man reset
Test mode sequense 5 s 10 s 15 s 20 s 25 s 30 s 35 s 40 s 45 s 50 s 55 s 60 s
LED Power/active 0 Flash X Flash X X X X X X 0 0
LED Alarm C (low level) 0 0 0 Flash Flash X X X X X Flash 0
LED Alarm B (middle level) 0 0 0 Flash 0 0 Flash X X X Flash X
LED Alarm A (high level) 0 0 0 Flash 0 0 0 0 Flash X Flash 0
Alarm C U=(>C,<B)
Alarm B U=(>B,<A)
Alarm A U>A

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LDM 250 450 650 Low
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LDM 250 450 650 Low
voltage Multipoint unit

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LDM 250 450 650 Low
voltage Multipoint unit
LDM 250 450 650 Low
voltage Multipoint unit

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LDM 250 450 650 Low
voltage Multipoint unit
LDM 250 450 650 Low
voltage Multipoint unit

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English
English
English
LDM 250/450/650 Low voltage Operating Manual
1. Table of Contents
2. Features.................................................................................................................................................10
3. Models ...................................................................................................................................................11
4. Function .................................................................................................................................................11
4.1 AUTO/MANUAL ALARM RESET .........................................................................................................11
4.2 ALARM TIME DELAY (T1) ....................................................................................................................11
4.3 RESET/TEST/SERVICE-BUTTON (7) .........................................................................................11
4.3.1 SERVICE MODE ...............................................................................................................................12
4.3.2 FAULT MODE...................................................................................................................................12
4.4 INTERNAL BUZZER AND 24VDC AUXILIARY OUTPUT.................................................................12
4.5 Remote sensors ......................................................................................................................................13
5Location/Installation ...........................................................................................................................13
5.1 ALARM LEVELS / CHANGING ALARM LEVELS .......................................................................13
5.2 Function Control ..............................................................................................................................13
6Technical Data......................................................................................................................................13

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2. Features
The LDM250, LDM450 and LDM650 are central units with two/four/six channels(sensors).
The LDM250/450/650 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 volts rated SPDT contacts
- Failsafe relay operation on power loss
- Audible alarm
- Low voltage output for auxiliary alarm indication.
Please Note!
The LDM250, LDM450 and LDM650 are normally supplied with default set alarm
thresholds. These must be verified or reset during commissioning. Alarm levels
must always be set on each channel for proper gas and detector type.
Default settings from factory:
Alarm level
Offset
Alarm C
1,0V
Alarm B
2,0V
Alarm A
3,0V
Alarm levels, factory settings are:
HFC, HFO, HCFC (ppm)
C=100
B=1000
A=2000
Table 3

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3. Models (sensors included)
Model
Used for
724-250-G1
two channels(sensors)
724-450-G1
four channels(sensors)
724-650-G1
six channels(sensors)
4. Function
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 illuminate
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 LEDs 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
initiate if it is configured with the respective alarm threshold and cannot be muted. Technicians
can inhibit the alarm by selecting ‘Service Mode’.
4.1 AUTO/MANUAL ALARM RESET
DIP switch (5) no3 on each channel’s control card manages the alarm reset function. “ON”
enables Auto reset and “OFF” enables Manual reset, via pressing “Reset/Test/Service”-button
(7).
4.2 ALARM TIME DELAY (T1)
DIP-switch (5) controls the alarm time delay for each channel.
no1 no2
on on No alarm delay
off on 1 minute delay
on off 10 minutes delay
off off 30 minutes delay
4.3 RESET/TEST/SERVICE-BUTTON (7)
Reset/Test/Service-functions is accessible via a pushbutton on the cover.
Pressing the “Reset/Test/Service”-button (7) on any channel for 5 seconds initiates the test
program. This sequentially energizes each LED and relay at five second intervals. All LEDs on the
chosen channel will go out when the test program has started.

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4.3.1 SERVICE MODE
Pressing the” Reset/Test/Service” button (7) for 10 seconds will inhibit all alarm functions for the
chosen channel for 60 minutes. Service mode is indicated by all LEDs on the chosen channel is
flashing. 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 pressing the
“Reset/Test/ Service”-button briefly.
4.3.2 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) no4 on the respective channel
card to 'ON'. The operation of the LEDs will remain unchanged.
4.4 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(no1), B(no2) or C(no3).
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.
Please Note!
After being powered off for prolonged periods the sensor may take several
minutes to stabilize during which time ‘false’ alarms may be initiated. Such ‘false’
alarm shall disappear within a few minutes.
n 4 FAULT DELAY: ON=4h DELAY, OFF= NO DELAY
n 1
n 2
n 3 ALARM RESET: ON=AUTO, OFF=MANUELL
ON
A
RESET/TEST
TEST TERMINAL
C
B
LED A
LED B
LED C
POWER
ALARM A
ALARM B
ALARM C
(-)
+ 5VDC
GV OFFSET

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4.5 Remote sensors
LDMR series is a range of remote sensors designed for use with the LDM units.
Low voltage LDM250, LDM450, or LDM650 units include either 2, 4, or 6 LDMR remote sensors
for detecting HFCs, HCFCs, and mixtures and carbon dioxide (CO2).
Please Note!
The sensors used in the LDMR series have limited selectivity and are therefore
not gas specific. Care should be taken when installing the equipment to minimize
any cross contamination from other gases or vapours.
For further guidance on specific applications contact us.
5Location/Installation
Correct location of the LDMR is essential to ensure optimum operation of the system. Special
consideration must be given to air movement and whether the gas to be detected is heavier or
lighter than air. For gases heavier than air (e.g. Refrigerants (HFC, HCFC) or CO2) the sensor
should ideally be located approximately 20cm above floor level. Connect the sensor according to
the wiring diagram.
NOTE! For unused channels a jumper (8) must be mounted and a >100 kohms resistor (attached)
must be installed between (+) and (S) to prevent open sensor alarms.
Otherwise, the channel will indicate a fault alarm.
When changing or replacing a LDMR a new calibration must be performed.
5.1 ALARM LEVELS / CHANGING ALARM LEVELS
The unit is normally supplied with default set alarm thresholds.
These must be verified or reset during commissioning.
To set or change the alarm thresholds you need a MCT150 Calibration tool and a small
screwdriver.
Full details regarding custom alarm set-points for a range of gases together with a detailed
procedure are outlined in specific data sheets. Multiple gases and alarm set-points can be
accommodated on a single LDM as each channel is totally independent.
5.2 Function Control
Testing the system is recommended to be done once a year. A basic function test can be
performed using MCT150. Extended control and calibration require test gas with a specific
concentration.
6Technical Data

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Standard Housing:
ABS/PC plastic, (IP67)
Power supply:
24 AC/ 24V DC, max 10VA
Status Indication:
Common Power LED
Individual LED channel indication of
sensor active and 3 alarm levels.
Inputs:
2, 4 or 6 channels 0-5VDC
Alarm levels:
3 levels/channel, individually set within 0,5...4,8V
Hysteresis:
alarm levels +- ~100mV
Output relays (4 off):
Volt free contacts, SPDT rated 230V AC / 5amps.
Output (voltage):
24VDC max 150mA
Ambient temp:
+-0 Deg C - + 50 Deg C
Sensor cable:
3 x 0,75mm2 max 50m
(Screened)
3 x 1,5mm2 max 150m
Dimensions:
180 x 255 x 60mm
Glands:
12 x M16
Specifications subject to change

Due to our continuing program of product improvements, specifications are subject to ch
ange without notice.
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