The MEAN WELL LAD-240A is a 13.8 V security and fire-alarm power supply with a 16.4 A CH1 load output and a 1 A CH2 battery-charging output, sharing a 240.12 W total rating. It integrates DC-UPS backup, TTL status monitoring and AC / battery maintenance switches.
Product Datasheet
Download MEAN WELL LAD-240 Datasheet (PDF)
The LAD-240 section is on PDF pages 16, 17, 18, 19, 20, 21, 22. Refer to the complete mechanical drawings and notes when planning installation.
Model and Output Ratings
Full model
LAD-240A
Series
LAD-240
CH1 output voltage
13.8 V
CH1 rated current
16.4 A
CH2 charge voltage
13.8 V
CH2 rated charging current
1 A
Rated total output power
240.12 W
CH1 current range
0–17.4 A
CH1 voltage adjustment
10.8–14.5 V
CH1 ripple and noise, maximum
150 mVp-p
CH1 voltage tolerance
±1.5%
CH1 line regulation
±0.5%
CH1 load regulation
±1.0%
CH1 supplies the load and CH2 charges an external battery. Both channels share the rated total output power; the charging channel is not an additional independent power allowance. Keep each channel within its rating and the combined load within the total power limit.
The CH1 VR adjustment covers the stated voltage range. Select a lead-acid or lithium-ion battery with a charging-voltage requirement and protection system suitable for this model. This model provides TTL status signals; UART communication and a buzzer are not specified for this version.
Input and Electrical Performance
Input voltage range
90–132 VAC / 180–264 VAC, selected by switch; 240–370 VDC
Input frequency
47–63 Hz
Typical efficiency
85.5%
Typical AC input current
4.4 A at 115 VAC; 2.4 A at 230 VAC
Typical cold-start inrush current
60 A at 115 VAC; 60 A at 230 VAC
Leakage current
Less than 0.5 mA at 240 VAC
Set-up / rise time at full load
2000 / 50 ms at both 115 and 230 VAC
Typical hold-up time at full load
16 ms at 230 VAC; 12 ms at 115 VAC
Battery static discharge current
Less than 100 µA
Switching frequency
65 kHz
The input-voltage selector defaults to 230 VAC. Set the correct 115 / 230 VAC range before operation; the two AC ranges are not one continuous universal range.
Unless otherwise stated, specifications are measured at 230 VAC, rated load and 25°C ambient. Ripple and noise use a 20 MHz bandwidth, a 12-inch twisted pair and parallel 0.1 µF / 47 µF capacitors. Voltage tolerance includes set-up tolerance, line regulation and load regulation.
Battery Backup and Protection
CH1 overload threshold
105–135%
CH2 overload threshold
90–110%
CH1 overvoltage threshold
15.5–18 V
Battery cutoff voltage
9.5 ± 0.5 V
Battery reverse-polarity protection
No damage; automatic recovery after the connection is corrected
Overvoltage and overtemperature response
Output shutdown; reapply input power to recover
If the AC input becomes abnormal, the DC-UPS function transfers the load to the external backup battery. Built-in AC and battery circuit switches provide maintenance control. The battery is external and is not included with the power supply.
With a battery connected to CH2, CH1 overload around 105–120% causes the unit to enter UPS mode. When the combined CH1 + CH2 output reaches around 125–135%, the output shuts down.
Without a battery, CH1 overload shuts down the output; remove the fault and reapply power.
CH2 uses constant-current limiting, recovers automatically after the fault is removed, and its fault does not stop CH1 operation. An external fuse in series with the battery is mandatory. Short-circuit, overload, overvoltage, overtemperature, battery undervoltage and reverse-polarity protection are provided.
TTL Status and Forced UPS Operation
CN2 pin 1, AC OK
Relative to pin 4: low = normal AC input; high/open = abnormal AC input
CN2 pin 2, battery disconnect / reverse polarity
Relative to pin 4: low = disconnected or reversed; high/open = connected normally
CN2 pin 3, battery low
Relative to pin 4: low = battery under undervoltage protection; high/open = normal battery
CN2 pin 4
GND
CN2 pin 5, battery full
Relative to pin 4: low = fully charged; high/open = charging
CN2 pin 6, discharge
Relative to pin 4: low = battery-backup discharge; high/open = main power working
CN2 pins 7 and 8
Short = forced-start UPS mode; open = normal operation
Status-output external voltage, maximum
50 VDC
Status-output sink current, maximum
30 mA
Status-output low level, maximum
0.3 V at 30 mA
Provide an external voltage source and pull-up resistor for the status signals. Observe the maximum applied voltage and sink current; the signal output is not an internal power source.
Battery-disconnected and reverse-polarity detection is available during the initial transmission at startup, rather than continuous detection at any time. Short CN2 pins 7 and 8 to force UPS operation for battery maintenance; opening them restores normal operation.
Terminal Connections and Mating Parts
TB1 pin 1
AC/L
TB1 pin 2
AC/N
TB1 pin 3
FG
TB1 pin 4
DC OUTPUT −V
TB1 pin 5
DC OUTPUT +V
TB1 pin 6
BAT−
TB1 pin 7
BAT+
CN2 mating housing
TKP DH2 or equivalent
CN2 mating terminal
TKP DHT-1S(LF) or equivalent
DC OUTPUT −V and BAT− must not be shorted. Keep load and battery wiring on their assigned terminals and connect protective earth to FG. Follow the mechanical drawing for connector orientation and the AC / battery switch positions.
Select mating parts for the actual circuit count and wire assembly. The catalogue identifies the housing and terminal references without specifying an included signal harness.
Cooling and Derating
Cooling arrangement
Built-in fan; follow the marked airflow direction
Working temperature
−20 to +60°C, subject to derating
Horizontal temperature curve
100% load from −20 to 50°C; 60% load at 60°C
Input-voltage load curve
115 V range: 80% at 90 VAC and 100% at 100–132 VAC; 230 V range: 100% at 180–264 VAC, 60 Hz
Working humidity
20–95% RH, non-condensing
Storage temperature and humidity
−30 to +85°C; 10–95% RH, non-condensing
Temperature coefficient
±0.03%/°C, 0–50°C
Vibration
10–500 Hz, 5 G; 10 minutes per cycle, 60 minutes along each X, Y and Z axis
Apply the input-voltage and temperature load limits together. Above 2000 m, reduce allowable ambient temperature by 3.5°C per 1000 m for fanless models or 5°C per 1000 m for fan-cooled models. Keep ventilation paths and the marked airflow direction clear.
Safety and EMC
Approved safety standards
UL 62368-1; BS EN / EN 62368-1; AS/NZS 62368.1; EAC TP TC 004
System design reference
GB 17945-2010
Withstand voltage
Input–output: 3 kVAC; input–FG: 2 kVAC; output–FG: 0.5 kVAC
Isolation resistance
Input–output, input–FG and output–FG: 100 MΩ at 500 VDC, 25°C and 70% RH
Conducted and radiated emissions
BS EN / EN 55032 (CISPR 32), Class A; EAC TP TC 020
ESD immunity
8 kV air / 6 kV contact; criterion A
Radiated immunity
BS EN / EN 61000-4-3: 10 V/m; criterion A
EFT / burst immunity
BS EN / EN 61000-4-4: 2 kV; criterion A
Surge immunity
BS EN / EN 61000-4-5: 1 kV line–line / 2 kV line–FG; criterion A
Conducted immunity
BS EN / EN 61000-4-6: 10 V; criterion A
Magnetic-field immunity
BS EN / EN 61000-4-8: 30 A/m; criterion A
This is a component for installation in final equipment. Catalogue EMC tests mount the supply on a 360 × 360 mm metal plate, 1 mm thick. The completed installation must be checked against the relevant EMC requirements.
The radiation-test setup additionally uses 13 × 26 × 30 NIZN magnetic loops or buckles on the battery-output wire. Include the applicable suppression arrangement in final-equipment EMC verification.
This model does not meet BS EN / EN 61000-3-2 harmonic-current requirements. In the EU, it must not be used on a public mains system rated at 220 VAC or above for end equipment with average or continuous input power above 75 W or for lighting, except where the catalogue exemption applies: professional equipment above 1000 W total rated input, or symmetrically controlled heating elements with total rated power no greater than 200 W.
Mechanical Installation and Reference Mass
Catalogue dimensions, L × W × H
215 × 115 × 30 mm
Drawing case number
207
Drawing dimensional tolerance
±1 mm
Mass, catalogue PACKING reference per unit
750 g
Catalogue packing
0.75 kg; 15 units / 12.25 kg / 0.7 CUFT
Minimum MTBF, Telcordia / MIL-HDBK-217F
1394.9K / 156.7K hours
Warranty
3 years
Use the case 207 drawing for the 215 mm enclosure length, 115 mm enclosure width, 30 mm height, and optional bracket layout. Side mounting holes are M4, with a 6 mm length limit; the longitudinal mounting reference is 150 mm.
Optional mounting bracket PGG2MHS012 is ordered separately. The accessory list calls for four bracket pieces per power-supply model; confirm the sales quantity when ordering. The installation drawing shows four M4 fixing points.
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