PTC-relays Type MSF220SE

PTC-Resistor-Relay, for Dry-Transformers , 2 PTC-circuits

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Part number

AC/DC 90 - 240 V
AC/DC 24 - 240 V

Product description


The PTC-resistor trip device MSF220SE monitors the winding temperature of machines and equipment. Signals, that can be used as ”early warning" or ”malfunction" (switching-off), are transmitted as soon as the admissible limit temperature is exceeded.
Two PTC-circuits can be connected to this unit. The integrated rise-delay time ensures a reliable mains voltage build-up.


  • 2 PTC resistor circuits, 1 to 6 PTC each (max. cold resistance of circuit 1500Ω each)
  • potential-free contact for alarm 1
  • potential-free contact for alarm 2
  • voltage of pin 3 is connectet to pin 1 with a time delay of 2 sec., replacing an additional timing relay.
  • alarm 3 for check of relay K3
  • LED´s signal state of relays K1 and K2
  • relay K3 picks up time-delayed
  • TEST-button for ALARM 1 and ALARM 2


Thanks to the delayed switching-on of the error message (approx. 2 s) after the switching-on, this device is especially suitable where an auxiliary voltage is not available and the secondary voltage of the monitored transformer is being used. The MSF220SE can furthermore be used advantageously when combining it with operating current releases. For additional devices, the control voltage is available at terminal 1 time-delayed. In case of a breakdown of the supply voltage, the control voltage is available at terminal 7 and can be used as a message. (Attention! This message will also be given for approx. 2 s. after switching-on.)

Functional description

PTC-circuits in closed-circuit current principle. When the closed-circuit current flows, both output relays K1, K2 are picked up. Approx. 2 sec. after switching on supply power, relay K3 picks up time-delayed, closing the contact circuits at terminals 31, 14 and 31, 24. As soon as the temperature of the early warning has been reached, relay K1 releases (terminal 31, 12 closed), the alarm 1 is given. If the temperature of malfunction is reached, also relay K2 releases (terminal 31, 22 closed). This alarm 2 can be used to switch off the equipment. If the temperature drops to approx. 5 °C below the temperature of malfunction or early warning, the relays K1 and K2 resp. are switched on again.
TEST: LED "ON" – flash -> +2 s -> Alarm 1 -> +3 s -> Alarm 2


Technical data


Rated supply voltage Us


AC/DC 90 - 240 V, AC 80 - 264 V, DC 80 - 297 V,  < 2 VA
AC/DC 24 - 240 V, AC 20 - 264 V, DC 21- 297 V, < 2 VA


Connectable PTC resistors


2 x 1...6 PTC according to DIN VDE V 0898-1-401 (formerly DIN 44081/82)


Switching point


< 4000 Ω


Output relay


2 x 1  change-over-contact (co)


Type of contact


Type 2 (see general technical information)


Test conditions


see general technical information


Rated ambient temperature


-20...+55 °C


Dimensions h x w x d


Design S12: 82 x 42 x 121 [mm]




on 35 mm DIN rail according to EN 60 715 or screws M4 (option)


Protection Housing/Terminals






approx. 210 g




Operating Manual

Operation manual (french)

Operation manual (italian)

Operation manual (spanish)

Operation manual (polish)