Automatic Phase Selector PEF-319


Automatic Phase Selector PEF-319 –

Voltage Type AC
Voltage (V) 220 – 240
Logic 3 Phase input and Single (best) phase output
Application Healthy phase selection, Uninterrupted power supply to load
Current (Amps) 30A direct and any load through 3 contactors
Relay output 3 x SPDT (30A)
Phase Switching Under voltage, Over voltage, Phase loss

5 in stock


PEF-319 universal automatic electronic phase switching device is designed to supply an industrial and domestic single phase 220/230/240 V, 50 Hz load from three-phase four-wire mains 3×380+N in order to maintain uninterrupted power supply of essential single-phase loads and protect them against unallowable voltage variations in the mains. According to the voltage presence and voltage quality on the phases, the PEF-319 will automatically select the optimum phase in limits range set by user and switch the single phase load supply to this phase:- If power is less than 6.6 kW (30 A), the load is energized directly from the PEF-319;- if power is more than 6.6 kW (30 A), the PEF-319 controls the magnetic contactor (MC) single phase coils of the corresponding power (MC are not included in supply complete package). The maximum and minimum voltage limits are set by user adjusting the potentiometers on the front panel as per requirement.

The electronic phase switch PEF-319 is a microcontroller-based digital device. User should make setting of trip threshold limits of PEF-319 – the minimal and maximal voltage values at which PEF-319 trips and switches off the load (or switches over to another phase). Phase L1 has the highest priority. It means that at normal parameters of voltage on all phases connected to PEF-319 (L1>L2>L3), the load will always be energized from phase L1. If on L1 the value is out of limits set by user, PEF-319 switches the load to the nearest by priority phase in not more than 0.2 seconds if the its voltage corresponds to the normal level. If the voltage on the reserve phases does not correspond to the trip set limits the load switches off. After the load had been switched to another phase and the voltage parameters had been restored on the priority phase, the load will be switched back to the priority phase in return time r (from 5 to 200 sec, settable) set by user. If r is in the position “∞”, the return to the priority phase will be performed only when voltage on the other phase goes out of the threshold limits.

In case when the voltage supplied on load goes lower than the minimal threshold limit the load switching over or switching off should be performed with a time delay of 12 seconds. When the voltage goes higher than the maximal threshold limit or goes 30 V lower than the minimal threshold limit, the load switching over or switching off will be performed with time delay of 0.2 seconds. During the load switching off the PEF-319 continues to perform the voltage control on all phases. When the voltage normalizes within the limit range on one of the phases.

        General information:

Device scopeControl and distribution device
Construction type (installation)On standard DIN-rail, 35 mm

Protection degree of:  – device

– terminals block



Climatic versionNC 3.1
Pollution rateII
Electric shock protection classII
Category of overloadII
Rated insulation voltage, V450
Rated impulse withstand voltage, kV2.5
Cross-section of connection terminal wires, mm22-4
Screw torque of terminal clams, N*m0.4

Basic technical characteristics:

Designation     Value
Nominal phase voltage, V230/240
Operating capability voltage, on single phase, V120
Mains frequency, Hz45 – 65
Trip threshold for UMIN,  V150 – 210
Trip threshold for UMAX, V230 – 280

Time delay range for return to the priority phase, sec

Note – If knob Тr is in position “¥” there is no return to the priority phase

5- 200
Time delay range of reclosing, Тon, sec1 – 600
Fixed time delay of switching over (switching off) for UMIN, sec12
Time of switching over to reserve phases, sec, not more0.2
Hysteresis (reset coefficient) on voltage, V5 – 7
Accuracy of threshold trip, V±3

Maximum switched current (active) of additional relay output contacts, A


Device operating capability phase voltage, V400
Short time allowable operating capability maximal phase voltage, V450
Power consumption (under load), VA, not more than10

Service life of output contacts:

  • Under load 30 A (active voltage), operations, not less than
  • Under load 5 A, operations, not less than

100 000

1 000 000

Overall dimensions, mm157 х 90.8 х 59
Weight, kg, not more than0.38
Mounting – on standard DIN-rail 35 mm. 
Mounting position – user defined. 

PEF-319 meets the requirements of: IEC 60947-1; ІEC 60947-6-2; CISPR 11; IEC 61000-4-2.

Harmful substances in concentration more than allowed are absent.

Additional information

Weight 0.5 kg

8 pole MCB size (W:158 x H:90.8 x D:59 mm)




DIN Rail


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