Permanent Over & Under Voltage Auxiliary

A permanent over voltage on the low voltage installation can occur due to accidental loss of neutral, faulty connection between phases (400Vac) instead of phase to neutral (230Vac) or presence of harmonics.

MZ209 & MZ214

Such permanent over voltage is different from transient over voltage, which is covered by surge protection device (SPD).

The permanent over voltage can result in :

  • Equipment failure
  • Overheating (reduction in length of life of equipment)
  • Electrical breakdown (risk of fire)
  • Deterioration in safety and protection of users.
Similarly, a permanent under voltage can also present a risk to the installation and equipment.

The over voltage auxiliary, MZ209, and combined over- and under-voltage auxiliary, MZ214, causes automatic opening of the electrical circuit by tripping the associated protection device (MCB, RCCB, RCBO) if there is a permanent over or under voltage detected on the network.


Features

  • Trip when the voltage decreases or increases out of the correct working voltage.
  • Prevents reclosing of the MCB/RCCB/RCBO until the voltage resumes to within the normal threshold.
  • Only 1 module width.
  • Need to connect only 2 wires to each auxiliary.
  • Mechanical indicator on the front face when auxiliary is activated.

General Characteristics

MZ209
Description
Acting / latching threshold over voltage
Tripping time
Rated voltage (Un)
Rated impulse voltage (Uimp)
Rated insulation voltage (Ui)
Electrical & mechanical endurance
 
Over voltage release 230Vac
  • Over voltage : 266Vac to 294Vac


  • Under voltage : NA
  • Over voltage : 10ms to 100ms


  • Under voltage : NA
230Vac 50/60Hz
4kV
500Vac
10,000 cycles
MZ214
Description
Acting / latching threshold over voltage
Tripping time
Rated voltage (Un)
Rated impulse voltage (Uimp)
voltage (Uimp) Rated insulation voltage (Ui)
Electrical & mechanical endurance
 
Combined Over & Under voltage release 230Vac
  • Over voltage : > 270Vac


  • Under voltage : 60Vac-195Vac
  • Over voltage : 100ms


  • Under voltage : 150ms-8s
230Vac 50/60Hz
4kV
450Vac
10,000 cycles

Diagrams