Skip to content
Safe Switchgears

SF001-SF031 · 3 sub-ranges

Single Phasing Preventers

Protect three-phase motors from single phasing, voltage unbalance and phase reversal. Available as basic fixed-trip units, auto-start models, and versions with an in-built star-delta timer.

Single Phasing Preventers

31 products shown

Basic Single Phasing Preventer
PMR-SF · SF001
Basic Single Phasing Preventer

Fixed 36-42V unbalance trip, 1 NO output, 415V 3ø direct.

View product →
Single Phasing Preventer, 1CO
PMR-SF1 · SF002
Single Phasing Preventer, 1CO

Fixed 36-42V unbalance trip with 1 CO changeover output.

View product →
Phase Monitoring Relay
PMR-SFV · SF003
Phase Monitoring Relay

Variable unbalance trip, 1 CO output, panel mount.

View product →
Single Phasing Preventer + Phase Reversal
PMR-Z · SF004
Single Phasing Preventer + Phase Reversal

Adds phase-sequence (reversal) protection to the basic preventer.

View product →
Basic SPP (wired, 36-42V)
PMR-SFW · SF005
Basic SPP (wired, 36-42V)

Basic preventer, 36-42V unbalance trip, PVC wire termination.

View product →
Basic SPP (wired, 42-50V)
PMR-SFWN · SF006
Basic SPP (wired, 42-50V)

Basic preventer, 42-50V unbalance trip, PVC wire termination.

View product →
SPP + Phase Reversal (wired, 36-42V)
PMR-ZW · SF007
SPP + Phase Reversal (wired, 36-42V)

Phase-reversal preventer, 36-42V unbalance, PVC wire termination.

View product →
SPP + Phase Reversal (wired, 42-50V)
PMR-ZWN · SF008
SPP + Phase Reversal (wired, 42-50V)

Phase-reversal preventer, 42-50V unbalance, PVC wire termination.

View product →
SPP, DIN-rail (basic)
PMR-RF · SF009
SPP, DIN-rail (basic)

Basic 36-42V unbalance preventer, DIN-rail mountable, 1 CO.

View product →
SPP, DIN-rail (variable)
PMR-RFV · SF010
SPP, DIN-rail (variable)

Variable 30-60V unbalance preventer, DIN-rail mountable, 1 CO.

View product →
SPP with auxiliary supply
PMR-AS1 · SF011
SPP with auxiliary supply

Basic unbalance preventer with separate auxiliary supply, DIN-rail, 1 CO.

View product →
SPP with auxiliary supply (variable)
PMR-AS1V · SF012
SPP with auxiliary supply (variable)

Variable unbalance preventer with auxiliary supply, DIN-rail, 1 CO.

View product →
Auto-Start SPP (basic)
HAX / MAX · SF013
Auto-Start SPP (basic)

Auto-start SPP with 30±5s ON-delay.

View product →
Auto-Start SPP (variable ON-delay)
HAX5 / MAX5 · SF014
Auto-Start SPP (variable ON-delay)

Auto-start SPP with variable 30s-5min ON-delay.

View product →
Auto-Start SPP + U/V cut-off
HBX / MBX · SF015
Auto-Start SPP + U/V cut-off

Auto-start SPP with under-voltage cut-off.

View product →
Auto-Start SPP + U/O-V cut-off
HCX / MCX · SF016
Auto-Start SPP + U/O-V cut-off

Auto-start SPP with under- and over-voltage cut-off.

View product →
Auto-Start SPP, Auto-Manual (basic)
SAY · SF017
Auto-Start SPP, Auto-Manual (basic)

Auto-start SPP with auto-manual switch, 30±5s ON-delay.

View product →
Auto-Start SPP, Auto-Manual (variable)
SAY5 · SF018
Auto-Start SPP, Auto-Manual (variable)

Auto-manual auto-start SPP, variable 30s-5min ON-delay.

View product →
Auto-Start SPP, Auto-Manual + U/V
SBY · SF019
Auto-Start SPP, Auto-Manual + U/V

Auto-manual auto-start SPP with under-voltage cut-off.

View product →
Auto-Start SPP, Auto-Manual + U/O-V
SCY · SF020
Auto-Start SPP, Auto-Manual + U/O-V

Auto-manual auto-start SPP with under & over-voltage cut-off.

View product →
Auto-Start SPP, Bypass (basic)
SAZ · SF021
Auto-Start SPP, Bypass (basic)

Auto-start SPP with auto-manual-bypass switch, 42-50V unbalance.

View product →
Auto-Start SPP, Bypass (variable unbalance)
SAZV · SF022
Auto-Start SPP, Bypass (variable unbalance)

Bypass-switch auto-start SPP with variable unbalance trip.

View product →
Auto-Start SPP, Bypass (variable ON-delay)
SAZ5 · SF023
Auto-Start SPP, Bypass (variable ON-delay)

Bypass-switch auto-start SPP, variable 30s-5min ON-delay.

View product →
Auto-Start SPP, Bypass + U/V
SBZ · SF024
Auto-Start SPP, Bypass + U/V

Bypass-switch auto-start SPP with under-voltage cut-off.

View product →
Auto-Start SPP, Bypass + U/O-V
SCZ · SF025
Auto-Start SPP, Bypass + U/O-V

Bypass-switch auto-start SPP with under & over-voltage cut-off.

View product →
Auto-Start SPP + Timer (2-button)
AG4 · SF026
Auto-Start SPP + Timer (2-button)

SPP with in-built timer for 2-push-button semi-automatic star-delta starters; effective in auto & manual modes.

View product →
Auto-Start SPP + Timer (3-button)
AG5 · SF027
Auto-Start SPP + Timer (3-button)

SPP with in-built timer for 3-push-button semi-automatic star-delta starters; effective in auto & manual modes.

View product →
Auto-Start SPP + Timer (3-button, auto only)
AG6 · SF028
Auto-Start SPP + Timer (3-button, auto only)

SPP with in-built timer for 3-push-button semi-automatic star-delta starters; effective only in auto mode.

View product →
SPP + Star-Delta Timer (bypass)
SFX · SF029
SPP + Star-Delta Timer (bypass)

Single-phasing protection plus built-in star-delta changeover; SPP bypass switch, no ON-delay.

View product →
SPP + Star-Delta Timer (auto-manual)
SFY · SF030
SPP + Star-Delta Timer (auto-manual)

SPP with star-delta changeover; auto-manual switch, effective in both modes.

View product →
SPP + Star-Delta Timer (door bypass)
SFZ · SF031
SPP + Star-Delta Timer (door bypass)

SPP with star-delta changeover; auto-manual switch with provision for panel-door mounted SPP bypass.

View product →