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Honeywell T7400 thermostat
I have a Honeywell T7400 Thermostat serving a portable class room. The thermostat controls a Temspec Unit Fan Ventilator with electric elements for heating - serves to ventilate (using some outside air/damper) as well as heat the space. There is an enthalpy controller with no real markings on it inside the unit venitilator with 4 contacts labelled 1, 2, 3, & 4, which connect to terminals 1, 2, 3, & 4 (respectively) of the above mentioned thermostat. Before I go jumping things to see if the thermostat is the culprit to the problem that the heat doesn't seem to be controlled properly, I want to know if these are just 2 sets of dry contacts (how do they correspond to todays thermostat terminal letters)? I have contacted Tempsec who is looking for a manual for me on their ventilator/wiring which is designed with this thermostat as standard equipment.
Class 'A' Gas Fitter - Certified Hydronic Systems Designer - Journeyman Plumber