Junction blocks with 3 contacts can be found here. An electronic part like this one has 4 ports. Junction blocks need to be kept at temperatures above -30°C to work properly. In fact, the junction blocks should have a maximum operating temperature of 80°C.
1503412 Features
Moisture Sensitivity Level: 1 (Unlimited) PLUSCON Series 3 Contacts Contact Plating: Gold Min Operating Temperature: -30°C Max Operating Temperature: 80°C
1503412 Applications
There are a lot of Phoenix Contact 1503412 Junction Blocks applications.