UNMA2 Series

UNMA2-125

Frame(A)UNMA2-125
TypeUNMA2-125SUNMA2-125H
Pole3,4
Product appearance
Rated currentInA16, 20, 25, 32, 40, 50, 63, 80,100,125
Rated voltageUe (V)AC400
Rated insulation voltageUi (V)AC690
Rated impulse voltageUimp(kV)AC8
Rated ultimate short circuit
breaking capacity
Icu (kA)AC
380 – 415V
3550
Rated service short circuit
breaking capacity
Ics (kA)AC
380 – 415V
2235
Utilisation categoryA
Polition degree3
Protection unitThermal-magnetic
Ir=(0.8-1)xIn

Im=(5-10)xIn

Operation lifeElectricalON-OFF3000
MechanicaON-OFF7000
Dimensions (mm) a-b-c-ca3P92-150-74-8992-150-92-107
4P122-150-74-89122-150-92-107
Weight(kg)3P1.01.0
4P1.11.4
ACCESSORIES
Shunt trip coil
Under voltage trip coil
Auxiliary contact
Alarm contact
Electrical motor operator
Rotary handle

UNMA2-250

Frame(A)UNMA2-250
TypeUNMA2-250SUNMA2-250H
Pole3,4
Product appearance
Rated currentInA100,125,140,160, 180,200, 225,250
Rated voltageUe (V)AC400
Rated insulation voltageUi (V)AC690
Rated impulse voltageUimp(kV)AC8
Rated ultimate short circuit
breaking capacity
Icu (kA)AC
380 – 415V
3550
Rated service short circuit
breaking capacity
Ics (kA)AC
380 – 415V
2535
Utilisation categoryA
Polition degree3
Protection unitThermal-magnetic
Ir=(0.8-1)xIn

Im=(5-10)xIn

Operation lifeElectricalON-OFF3000
MechanicaON-OFF7000
Dimensions (mm) a-b-c-ca3P107-165-94-114107-165-111-131
4P142-165-94-114142-165-111-131
Weight(kg)3P5.75.7
4P7.57.5
ACCESSORIES
Shunt trip coil
Under voltage trip coil
Auxiliary contact
Alarm contact
Electrical motor operator
Rotary handle

UNMA2-400

Frame(A)UNMA2-400
TypeUNMA2-400SUNMA2-400H
Pole3,4
Product appearance
Rated currentInA225,250, 315,350,400
Rated voltageUe (V)AC400
Rated insulation voltageUi (V)AC690
Rated impulse voltageUimp(kV)AC8
Rated ultimate short circuit
breaking capacity
Icu (kA)AC
380 – 415V
6580
Rated service short circuit
breaking capacity
Ics (kA)AC
380 – 415V
4260
Utilisation categoryA
Polition degree3
Protection unitThermal-magnetic
Ir=(0.8-1)xIn

Im=(5-10)xIn

Operation lifeElectricalON-OFF2000
MechanicaON-OFF4000
Dimensions (mm) a-b-c-ca3P150-257-115,5-115,5
4P198-257-115,5-115,5
Weight(kg)3P5.75.7
4P7.57.5
ACCESSORIES
Shunt trip coil
Under voltage trip coil
Auxiliary contact
Alarm contact
Electrical motor operator
Rotary handle

UNMA2-600

Frame(A)UNMA2-630
TypeUNMA2-630SUNMA2-630H
Pole3,4
Product appearance
Rated currentInA400,500,630
Rated voltageUe (V)AC400
Rated insulation voltageUi (V)AC690
Rated impulse voltageUimp(kV)AC8
Rated ultimate short circuit
breaking capacity
Icu (kA)AC
380 – 415V
6580
Rated service short circuit
breaking capacity
Ics (kA)AC
380 – 415V
4260
Utilisation categoryA
Polition degree3
Protection unitThermal-magnetic
Ir=(0.8-1)xIn

Im=(5-10)xIn

Operation lifeElectricalON-OFF2000
MechanicaON-OFF4000
Dimensions (mm) a-b-c-ca3P182-270-120-155
4P240-270-120-155
Weight(kg)3P5.75.7
4P7.57.5
ACCESSORIES
Shunt trip coil
Under voltage trip coil
Auxiliary contact
Alarm contact
Electrical motor operator
Rotary handle

UNMA2-800

Frame(A)UNMA2-800
TypeUNMA2-800MUNMA2-800H
Pole3,4
Product appearance
Rated currentInA700,800
Rated voltageUe (V)AC400
Rated insulation voltageUi (V)AC690
Rated impulse voltageUimp(kV)AC8
Rated ultimate short circuit
breaking capacity
Icu (kA)AC
380 – 415V
7580
Rated service short circuit
breaking capacity
Ics (kA)AC
380 – 415V
5060
Utilisation categoryA
Polition degree3
Protection unitThermal-magnetic
Ir=(0.8-1)xIn

Im=(5-10)xIn

Operation lifeElectricalON-OFF1500
MechanicaON-OFF4000
Dimensions (mm) a-b-c-ca3P210-280-115,5-155
4P280-280-115,5-155
Weight(kg)3P9.59.5
4P12.512.5
ACCESSORIES
Shunt trip coil
Under voltage trip coil
Auxiliary contact
Alarm contact
Electrical motor operator
Rotary handle

Overview

UNMF1-UNMF2-UNMF3 (fixed type), UNMA1- UNMA2 (adjustable type), UNML1-UNML2-UNML3 (earth leakage type) series moulded case circuit breakers are new versions developed by combining with the advantages of the international similar products and the demand of the market both at domestic and international.
The rated insulation voltage of our moulded case circuit breaker is up to 690V, applied to the power distribution network with AC 50-60 Hz, rated voltage 690V, rated current 800A. They are used for power distribution, circuit protection and avoiding the damage of power equipment from overload, short circuit, under voltage etc. At the same time, they can also be used to protect infrequent starting of motor, overload, short circuit and under voltage.
This product is small volume, high breaking, short flashover, etc. They can be installed vertically and horizontally.
Union MCCBs comply with the following international standards;
IEC 60947-1
Low-voltage switchgear and controlgear
• Part 1: General rules
IEC 60947-2
Low-voltage switchgear and controlgear
• Part 2: Circuit-breakers

Advantages

1. Small Volume
Our products has small volume, for example, the dimension of 125 shell product is same as original 63 shell product. Their installation dimensions can meet customer personal demand.
2. Same dimension
With same shell level, the installation dimension is completely same with different breaking capacity (C,S,M,H) and different functions (fixed, leakage).
3. Reasonable functional parameter
Moulded case circuit breaker can setting protection parameters such as overload long time delay inverse time, short circuit instantaneous action etc. Users can set the required protection features themselves, so that it makes more reasonable for the high and low level of circuit breaker to be used in distribution network.

Working Environment And Installation Conditions

1. Altitude below 2000m.
2. The surrounding medium temperature can’t be higher than +40°C (for Marine product is +45°C)
norless than -5°C.
3. Can not be influenced by moist air.
4. Can not be influenced by mould.
5. Can not be influenced by nuclear radiation.
6. The largest gradient is 22.5°.
7. Can work normally under the normal vibration of ship.
8. Can work normally under the earthquake (4g).
9. Where there is no explosion danger medium and the medium which will not corrode metals, no
gas that can damage the insulation and no conductive dust.
10. Where there is no heavy rain or snow.

Breaker Composition Accessories

Operating Characteristics

When ambient temperature is ±40°C, for distribution breaker power on for every pole, inverse time limit characteristics of no temperature
compensation is in the following sheet.

Test currentCurrent timeAgreed timeBegining condition
Agreed no tripping current1.05 In≤63 63<1h Cold condition
 ≥1h
 Agreed tripping current 1.30 <1h <2h Thermal condition

When ambient temperature is ±40°C, for electromotor pretection breaker, power on for every pole, inverse time limit characteristics of no temperature compensation is in the following sheet.

Test currentCurrent timeAgreed timeBegining condition
Agreed no tripping current1.0In≤800Cold condition
≥2h
 Agreed tripping current1.2<2h Thermal condition

Operating Characteristics On The Condition Of Short Circuit:

1.For instantaneous trip of distribution breaker, short circuit current is 10In.
2.For instantaneous trip of electromotor breaker, short circuit current is 12In.
3.For instantaneous trip, its accuracy is 20%.

Current Limiting

The assumed fault current (lsc) is the short-circuit current that would flow, if there were no limitation, at the point of the installation where the circuit breaker is placed.

Since the fault current is eliminated in less than one half-period, only the first peak current (asymmetrical peak l) need to be considered. This is a function of the installation fault cos θ.

The back-electromotive force is the arc voltage Ua due to the resistance of the arc developing between the contacts on separation. Its speed of development depends on the contact separation speed.

As shown in the figure above, as from the time ts when the contacts separate, the back less than the assumed fault current flow through when a short-circuit occurs. The circuit breaker limitation capacity defines the way it reduces the let through current under short-circuit conditions.

The thermal stress of the limited current is the area (shaded) defined by the curve of the square of the limited current l2sc (t). If there is no limitation, this stress would be the area, far larger, that would be defined by the curve of the square of the assumed current. For an assumed short-circuit current lsc, limitation of this current to 10% results in less than 1% of assumed thermal stress.

Union MCCBs are current limiting MCCBs and can reduce both the peak fault current and energy that reach downstream equipment to a tolerable level.Thus, motors and cables connected to the system will not be exposed to high Let through energy. With this,the current limiting MCCB helps in using lower size devices and cables, resulting in cost efficient control system.

Union MCCBs have special contact desing to provide current limitation. The advantages of current limitation are given as below :

Harmful Effects Of Short-CircuitsLimitation Effects
ElectromagneticReduction of magnetic fields, thus less risk of disturbing neighbouring measurement instruments.
MechanicalPaek current limited, thus reduced electromagnetic forces, mess risk deformation or breakage at electrical contact level.
ThermaLimited thermal stress (reduction of amplitude and duration of current flow), thus: temperature rise of conductors less marked, increased life time of busbar trunking.

Application

The Union MCCBs are suitable for wide range of applications;

  • • Feeder/Cable Protection
  • • Transformer protection
  • • Generator Protection
  • • Capacitor Protection
  • • Motor protection
  • • DC Network protection
  • • 400 Hz. Systems
  • • Earth Leakage Protection

Operating Characteristics