Low Cost execution for the monitoring of dry transformers. Alarm 1 with relay in closedcircuit current mode for preliminary warning, releases at over-temperature at PTC-set 1 and serves at the same time as functional monitoring. Alarm 2 in operating current mode. Thus no wiping signal occurs when switching on the supply voltage on. Additional terminals enable comfortable wiring from supply voltage to relays K1 and/or K2. 2-PTC resistor sets 2 output relays 1 change-over contact (co) / 1 normally open contact (no) TEST-button, for alarm 1 and 2 power on green LED red LEDs for alarm 1 and 2 K-type housing, vertically arranged terminals, 22,5 mm wide for attachment on DIN rail 35 mm or with 2 screws M4