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Mean Well LAD-120D Security/Fire Alarm PSU with Battery Charger/UPS, 120W, 55.2V 1.21A

built-in battery charger and UPS functionTTL signals for status detectionforced UPS mode for battery maintenance1U low profile
SKU LAD-120D
$38.73 USD
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Model

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LAD-120D
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Overview

LAD-120D is the CH1: 55.2V / CH2: 55.2V output model of this series: rated current CH1: 1.21A / CH2: 1A(Battery Charger), rated power 121.99W, typical efficiency 88%.

LAD-120 series is a 120W economical AC/DC low profile security power supply with UPS function. Adopting the input range from 90Vac to 264Vac and supports output 13.8V, 27.6V, 41.5V and 55.2Vdc. With high efficiency up to 88% and built-in AC, battery switch for easy maintenance. In addition, LAD-120 series also provide TTL signals for AC OK, battery disconnect, battery reverse polarity (No damage), battery low detection, battery full and discharge, to allow easy integration into security and fire systems directly.

Features

  • Built-in battery charger and UPS function
  • TTL signals for status detection: AC OK, Battery disconnect, Battery reverse polarity, Battery low, Battery full and Discharge
  • Built-in AC and battery circuit ON/OFF switches enhance safetyness during maintenance
  • Forced UPS mode for battery maintenance
  • Protections: Short circuit / Overload / Over voltage / Over temperature / Battery low voltage / Battery reverse polarity (No damage)
  • -20 ~ +60℃ wide operating temperature
  • Output voltage adjustable (-20%~+5%) for CH1 by VR
  • Suitable for lead acid and lithium-ion batteries
  • Design refer to GB17945 system requirement
  • 1U low profile (30 mm)
  • 3 years warranty

Specifications

LAD-120DSpecifications from the official datasheet (2024-10-30 edition)

OUTPUT

OUTPUT NUMBER
CH1 / CH2
DC VOLTAGE
CH1: 55.2V / CH2: 55.2V
RATED CURRENT
CH1: 1.21A / CH2: 1A(Battery Charger)
CURRENT RANGE
CH1: 0 ~ 2.21A / CH2: --------
RATED POWER
121.99W
RIPPLE & NOISE (max.)Note.2
CH1: 360mVp-p / CH2: --------
VOLTAGE ADJ. RANGE
Ch1: 43.5 ~ 58V
VOLTAGE TOLERANCENote.3
CH1: ±1.0% / CH2: --------
LINE REGULATION
CH1: ±0.5% / CH2: --------
LOAD REGULATION
CH1: ±0.5% / CH2: --------
SETUP, RISE TIME
500ms, 40ms/230VAC 500ms, 40ms/115VAC at full load
HOLD UP TIME (Typ.)
40ms/230VAC 9ms/115VAC at full load
BATTERY STATIC DISCHARGE CURRENT
<100μA

INPUT

VOLTAGE RANGE
90 ~ 264VAC 127 ~ 370VDC
FREQUENCY RANGE
47 ~ 63Hz
EFFICIENCY (Typ.)
88%
AC CURRENT (Typ.)
2.5A/115VAC 1.5A/230VAC
INRUSH CURRENT (Typ.)
COLD START 30A/115VAC 55A/230VAC
LEAKAGE CURRENT
0.5mA / 240VAC

PROTECTION

OVERLOAD
CH1:105 ~ 135% CH2:90 ~ 110% Protection type : CH1 OLP, CH2 with battery: The unit will enter to UPS mode when CH1 is around 105%~160%, when total output of CH1 + CH2 reach around 125%~135% output hiccup(120D shuts down) CH1 OLP, CH2 without battery:Hiccup mode o/p voltage, recovers automatically after fault condition is removed (120D shuts down,re-power on to removed) CH2 : Constant current limiting; fault condition does not affect CH1 working,recovers automatically after fault condition is removed (External fuse is mandatory in series connection with battery for protection)
OVER VOLTAGE
CH1:61 ~ 71V Protection type : Shut down o/p voltage, re-power on to removed
OVER TEMPERATURE
Protection type : Shut down o/p voltage, re-power on to removed
BATTERY REVERSE POLARITY
Protected when reverse polarity , no damage, recovers automatically after fault condition is removed
BATTERY CUTOFF
43V±0.5V

FUNCTION

AC OK
TTL signal, High / Open : AC Fail ; Low : AC OK ; Ice : max. 30mA@ 50VDC
BATTERY DISCONNECT/ REVERSE POLARITY
TTL signal, High / Open : Battery connect/normal ; Low : Battery disconnect/reverse polarity; Ice : max. 30mA@ 50VDC
BATTERY LOW
TTL signal, High / Open : Battery normal ; Low : Battery low; Ice : max. 30mA@ 50VDC
BATTERY FULL
TTL signal, High / Open : Battery charging ; Low : Battery full ; Ice : max. 30mA@ 50VDC
DISCHARGE
TTL signal, High / Open : Charge ; Low : Discharge ; Ice : max. 30mA@ 50VDC

ENVIRONMENT

WORKING TEMP.
-20 ~ +60℃ (Refer to "Derating Curve")
WORKING HUMIDITY
20 ~ 95% RH non-condensing
STORAGE TEMP., HUMIDITY
-30 ~ +85℃, 10 ~ 95% RH non-condensing
TEMP. COEFFICIENT
±0.03%/℃ (0 ~ 50℃)
VIBRATION
10 ~ 500Hz, 5G 10min./1cycle, 60min. each along X, Y, Z axes

SAFETY & EMC

SAFETY STANDARDS
UL62368-1, BS EN/EN62368-1, AS/NZS62368.1, EAC TP TC 004 approved; Design refer to GB 17945-2010
WITHSTAND VOLTAGE
I/P-O/P:3KVAC I/P-FG:2KVAC O/P-FG:0.5KVAC
ISOLATION RESISTANCE
I/P-O/P, I/P-FG, O/P-FG:100M Ohms / 500VDC / 25℃/ 70% RH
EMC EMISSIONNote 4
ParameterStandardTest Level
ConductedBS EN/EN55032 (CISPR32), EAC TP TC 020Class A
RadiatedBS EN/EN55032 (CISPR32), EAC TP TC 020Class A
Harmonic Current (Note 5)BS EN/EN61000-3-2Class A
EMC IMMUNITY
ParameterStandardTest Level
ESDBS EN/EN61000-4-2Level 3, 8KV air; Level 2, 6KV contact; criteria A
RadiatedBS EN/EN61000-4-3Level 3, 10V/m; criteria A
EFT / BurstBS EN/EN61000-4-4Level 3, 2KV; criteria A
SurgeBS EN/EN61000-4-5Level 3, 1KV/Line-Line ;2KV/Line-FG ;criteria A
ConductedBS EN/EN61000-4-6Level 3, 10V; criteria A
Magnetic FieldBS EN/EN61000-4-8Level 4, 30A/m; criteria A

OTHERS

MTBF
1509.9K hrs min. Telcordia SR-332 (Bellcore); 209.4K hrs min. MIL-HDBK-217F (25℃)
DIMENSION
159*97*30mm (L*W*H)
PACKING
0.42Kg; 30pcs/13.6Kg/0.77CUFT
Test conditions and notes6
  1. 1. All parameters NOT specially mentioned are measured at 230VAC input, rated load and 25℃ of ambient temperature.
  2. 2. Ripple & noise are measured at 20MHz of bandwidth by using a 12" twisted pair-wire terminated with a 0.1μF & 47μF parallel capacitor.
  3. 3. Tolerance : includes set up tolerance, line regulation and load regulation.
  4. 4. The power supply is considered a component which will be installed into a final equipment. All the EMC tests are been executed by mounting the unit on a 360mm*360mm metal plate with 1mm of thickness. The final equipment must be re-confirmed that it still meets EMC directives. For guidance on how to perform these EMC tests, please refer to “EMI testing of component power supplies.” (as available on https://www.meanwell.com//Upload/PDF/EMI_statement_en.pdf )
  5. 5. Test harmonic current at 85% load.
  6. 6. The ambient temperature derating of 3.5℃/1000m with fanless models and of 5℃/1000m with fan models for operating altitude higher than 2000m(6500ft).

Technical drawings

LAD-120D Block Diagram
Block Diagram
LAD-120D Suggested Application
Suggested Application
LAD-120D Illustration (page 5)
Illustration (page 5)
LAD-120D Illustration (page 5)
Illustration (page 5)
LAD-120D Illustration (page 5)
Illustration (page 5)
LAD-120D Dimensions (mm)
Dimensions (mm)
LAD-120D Mechanical Specification
Mechanical Specification

Typical applications

  • Fire emergency and evacuation system
  • Public safety battery back-up
  • Security system
  • Uninterruptible DC-UPS system
  • Central monitoring system
  • Industrial automation

Downloads

FAQ

What is the Mean Well LAD-120D designed for?

The LAD-120D is a 120W security and fire alarm power supply with a built-in battery charger and UPS function. It is intended for applications that need regulated 55.2V output plus backup power support and status monitoring features.

What are the main electrical ratings of the LAD-120D?

This model is rated for 121.99W output with a nominal output voltage of 55.2V and rated current of 1.21A. Its AC input range is 90 to 264VAC, and it also supports 127 to 370VDC input.

Does the LAD-120D support battery backup operation?

Yes. The LAD-120D includes a built-in battery charger and UPS function, and UPS mode can also be force-started by shorting pins 7 and 8 of CN2. The charger output is rated at 1A on CH2.

What status signals are available on the LAD-120D?

This power supply provides TTL status signals for AC OK, battery disconnect, battery reverse polarity, battery low, battery full, and discharge. These signals make it suitable for systems that need power and battery condition monitoring.

What protection features does the LAD-120D include?

The LAD-120D includes protection for overload, over voltage, over temperature, battery low voltage (cutoff at 43V±0.5V), and battery reverse polarity. The battery reverse polarity protection is specified as no-damage protection.

Can the LAD-120D be used in demanding temperature conditions?

Yes. This model is rated for operation from -20°C to +60°C, with load derating per the derating curve, which suits a wide range of indoor equipment environments. Buyers should still confirm that the final enclosure and system conditions stay within the product's specified operating range.

How compact is the Mean Well LAD-120D?

The LAD-120D uses a low-profile design with dimensions of 159 x 97 x 30 mm. It weighs 0.42 kg, which helps when space and panel density matter in security or fire system builds.

What certifications and compliance standards does the LAD-120D meet?

The LAD-120D is approved to UL62368-1, BS EN/EN62368-1, AS/NZS62368.1, and EAC TP TC 004. Its design also refers to GB 17945-2010, and listed EMC standards include EN55032 Class A and EN61000-4 series requirements.

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Other LAD Series Models

19 other models
ModelPower Voltage Current IP RatingPrice
Mean Well LAD-600B Security/Fire Alarm PSU with Battery Charger/UPS, 600W, 27.6V, TTL Signal 18.74A 600.02W 27.6V 18.74A IP20$85.20 View
Mean Well LAD-600DU Security/Fire Alarm PSU with Battery Charger/UPS, 600W, 55.2V, UART Signal 7.87A 600.02W 55.2V 7.87A IP20$91.35 View
Mean Well LAD-600D Security/Fire Alarm PSU with Battery Charger/UPS, 600W, 55.2V, TTL Signal 7.87A 600.02W 55.2V 7.87A IP20$85.20 View
Mean Well LAD-600CU Security/Fire Alarm PSU with Battery Charger/UPS, 600W, 41.5V, UART Signal 11.45A 599.67W 41.5V 11.45A IP20$91.35 View
Mean Well LAD-600C Security/Fire Alarm PSU with Battery Charger/UPS, 600W, 41.5V, TTL Signal 11.45A 599.67W 41.5V 11.45A IP20$85.20 View
Mean Well LAD-600BU Security/Fire Alarm PSU with Battery Charger/UPS, 600W, 27.6V, UART Signal 18.74A 600.02W 27.6V 18.74A IP20$91.35 View
Mean Well LAD-360DU Security/Fire Alarm PSU with Battery Charger/UPS, 360W, 55.2V, UART Signal 5.03A 360.46W 55.2V 5.03A IP20$62.12 View
Mean Well LAD-360D Security/Fire Alarm PSU with Battery Charger/UPS, 360W, 55.2V, TTL Signal 5.03A 360.46W 55.2V 5.03A IP20$51.83 View
Mean Well LAD-360CU Security/Fire Alarm PSU with Battery Charger/UPS, 360W, 41.5V, UART Signal 7.14A 358.56W 41.5V 7.14A IP20$62.12 View
Mean Well LAD-360C Security/Fire Alarm PSU with Battery Charger/UPS, 360W, 41.5V, TTL Signal 7.14A 358.56W 41.5V 7.14A IP20$51.83 View
Mean Well LAD-360BU Security/Fire Alarm PSU with Battery Charger/UPS, 360W, 27.6V, UART Signal 11.5A 358.8W 27.6V 11.5A IP20$62.12 View
Mean Well LAD-360B Security/Fire Alarm PSU with Battery Charger/UPS, 360W, 27.6V, TTL Signal 11.5A 358.8W 27.6V 11.5A IP20$51.83 View
Mean Well LAD-240D Security/Fire Alarm PSU with Battery Charger/UPS, 240W, 55.2V 3.4A 242.88W 55.2V 3.4A IP20$47.98 View
Mean Well LAD-240C Security/Fire Alarm PSU with Battery Charger/UPS, 240W, 41.5V 4.78A 239.87W 41.5V 4.78A IP20$46.98 View
Mean Well LAD-240B Security/Fire Alarm PSU with Battery Charger/UPS, 240W, 27.6V 7.7A 240.12W 27.6V 7.7A IP20$45.98 View
Mean Well LAD-240A Security/Fire Alarm PSU with Battery Charger/UPS, 240W, 13.8V 16.4A 240.12W 13.8V 16.4A IP20$44.98 View
Mean Well LAD-120C Security/Fire Alarm PSU with Battery Charger/UPS, 120W, 41.5V 1.9A 120.35W 41.5V 1.9A IP20$38.73 View
Mean Well LAD-120B Security/Fire Alarm PSU with Battery Charger/UPS, 120W, 27.6V 3.4A 121.4W 27.6V 3.4A IP20$38.73 View
Mean Well LAD-120A Security/Fire Alarm PSU with Battery Charger/UPS, 120W, 13.8V 7.7A 120W 13.8V 7.7A IP20$38.73 View
Mean Well LAD-120D Security/Fire Alarm PSU with Battery Charger/UPS, 120W, 55.2V 1.21A - LAD-120D - powersupplymall.com
Mean Well

Mean Well LAD-120D Security/Fire Alarm PSU with Battery Charger/UPS, 120W, 55.2V 1.21A

$38.73 USD

LAD-120D is the CH1: 55.2V / CH2: 55.2V output model of this series: rated current CH1: 1.21A / CH2: 1A(Battery Charger), rated power 121.99W, typical efficiency 88%.

LAD-120 series is a 120W economical AC/DC low profile security power supply with UPS function. Adopting the input range from 90Vac to 264Vac and supports output 13.8V, 27.6V, 41.5V and 55.2Vdc. With high efficiency up to 88% and built-in AC, battery switch for easy maintenance. In addition, LAD-120 series also provide TTL signals for AC OK, battery disconnect, battery reverse polarity (No damage), battery low detection, battery full and discharge, to allow easy integration into security and fire systems directly.

Features

  • Built-in battery charger and UPS function
  • TTL signals for status detection: AC OK, Battery disconnect, Battery reverse polarity, Battery low, Battery full and Discharge
  • Built-in AC and battery circuit ON/OFF switches enhance safetyness during maintenance
  • Forced UPS mode for battery maintenance
  • Protections: Short circuit / Overload / Over voltage / Over temperature / Battery low voltage / Battery reverse polarity (No damage)
  • -20 ~ +60℃ wide operating temperature
  • Output voltage adjustable (-20%~+5%) for CH1 by VR
  • Suitable for lead acid and lithium-ion batteries
  • Design refer to GB17945 system requirement
  • 1U low profile (30 mm)
  • 3 years warranty

Typical applications

  • Fire emergency and evacuation system
  • Public safety battery back-up
  • Security system
  • Uninterruptible DC-UPS system
  • Central monitoring system
  • Industrial automation

Model

  • 120W 55.2V
  • 240W 55.2V
  • 360W 55.2V
  • 360W UART 55.2V
  • 600W 55.2V
  • 600W UART 55.2V
View product