ES-8166 Rev.3

MDHA

Lightning Surge Protectors for
Electronics Equipment M-RESTER

LIGHTNING SURGE PROTECTOR
FOR POWER SUPPLY USE

(DC power use; life monitor)
Functions & Features
•Designed specifically for DC power supplies up to 5 amps
•Life monitor function helps you to decide when you should replace the M-RESTER; reduces maintenance and prevents downtime
•LED display and alarm contact output indicate the degradation and life span of the surge protection circuits
•No power supply interruption even when the unit is degraded or at the end of its life

DEL: MDHA–[1]

ORDERING INFORMATION

• Code number: MDHA-[1]
Specify a code from below for [1].
  (e.g. MDHA-24)

[1] OPERATIONAL VOLTAGE

12: 12 V DC
24: 24 V DC

GENERAL SPECIFICATIONS

Construction: Plug-in
Connection: M3.5 screw terminals (torque 0.8 N·m)
Screw terminal: Chromated steel
Housing material: Flame-resistant resin (black)
Alarm indicators
Power: The green LED turns on while the circuit is alive and the internal fuse on the voltage limiter side is not blown; and is off when the power supply is removed or this fuse is blown.
Alarm: Tricolor LED (green/amber/red)
•Remains off when the power supply is first turned on.
•Green: The unit has received one or more surges.
•Amber: Replacement is recommended.
•Red: The life span has ended.
Alarm contact
The N.C. contact is on when the life span of the discharge elements has ended, when the voltage limiter has degraded, when the fuses are blown, and/or when the power supply is removed.
Rating: 125 V AC @ 0.5 A (cos ø = 1)
30 V DC @ 1 A (resistive load)
Maximum switching voltage: 125 V AC or 110 V DC
Maximum switching power: 62.5 VA or 30 W
Minimum load: 5 V DC @ 1 mA

INSTALLATION

Operating temperature: -5 to +55°C (23 to 131°F)
Operating humidity: 30 to 90 %RH (non-condensing)
Mounting: Surface or DIN rail
Weight: 500 g (1.1 lb)

PERFORMANCE

Operational line voltage:
  10.8 – 13.2V DC (MDHA-12)
  21.6 – 26.4V DC (MDHA-24)
Discharge voltage (peak voltage)
• Line to line:
  ±15 V min. (MDHA-12)
  ±30 V min. (MDHA-24)
• Line to ground: ±160 V min.
Max. surge voltage (Up)
• Line to line:
  ±80 V max. (MDHA-12)
  ±120 V max. (MDHA-24)
• Line to ground: ±700 V max.
(This is the maximum voltage that could pass through M-RESTER. Protected equipment must be able to withstand this voltage for a very short time period.)
Response time:
• Line to line: ≤ 4 nsec.
• Line to ground: ≤ 20 nsec.
Leakage current 
• Line to line: ≤ 40 mA @ 13.2 V DC (MDHA-12)
  ≤ 40 mA @ 26.4 V DC (MDHA-24)
• Line to ground: ≤0.1 mA @ 160 V DC
Discharge current capacity: 10000 A (8/ 20 μsec.)
Maximum load current: 5 A
Insulation resistance: ≥ 100 MΩ with 500 V DC
Dielectric strength: 1500 V AC @ 1 minute
(line or ground to alarm output)
Internal series resist.: ≤ 0.2 Ω including return

EXTERNAL VIEW

GROUNDING

EXTERNAL DIMENSIONS & TERMINAL ASSIGNMENTS unit: mm [inch]

SCHEMATIC CIRCUITRY & CONNECTION DIAGRAM