Connecting multiple gutter sensors to SCE-120
If the ETO2 is configured as a one-zone application - you can connect two ETOR-55 sensors and one ambient temperature sensor to control this zone.
If the ETO2 is configured as a two-zone application – you can connect only one ETOR-55 per zone and one ambient temperature sensor for the combined application.
It is not possible to connect two ETOR-55 sensors to a set of terminals intended for one sensor - all readings would be wrong. Only exception is the terminals for sensor heating.