2nd Transformer on EK2000 Energy Manager

Brent H.

Greetings,

Trying to help a friend hook up a Wi-Fi Honeywell thermostat to their 12 zone Energy Manager. The back of the Energy Manager has 2 transformers but only one is tied into the A1/A2 terminals. Wondering if I can use the second transformer for the thermostat since I think the system is probably close to max. on the single 50VA transformer. (7 zone valves x 7 VA each). EK shows paralleling the transformers if needed.

Wondering if the Energy Manager ships with 2 but installer only hooked one up.

Thanks

STEVEusaPA

You would need two transformers for 12 zones. You're probably squeaking by on one transformer because usually, not all the zone valves operate at once. But they may after an extended power failure.
EK has specific wiring diagrams for their manager with different wifi thermostats.

Brent H.

@STEVEusaPA

My preference is to wire it directly to the Energy Manager and use terminal A2 for the common. It is a valid setup per the EK drawings since it is not a power robbing thermostat. Would like to tie the second transformer in parallel with the first to provide safety margin for the zone valves and power the thermostat. Do you see any issue with this? Odd that the 2nd transformer isn’t hooked up.

Roger

Thank you for your post, @Brent H. , and for @STEVEusaPA 's helpful reply. The 12 zone manager needs to have both transformers connected in parallel to A1 and A2 to support the power requirements of thermostats, zone valves, relays, and other functions of the Energy Manager. Since you are using a Honeywell Wi-Fi thermostat and a C wire in addition to Red and White wires, make sure that the C-wire connects to A2 and the Red wire connects to A1. All of the specific thermostat W-wires connect to the manager T1, T2, or T3 terminals (for zones 1, 2, and 3 respectively). Remember that it may take some time to charge up the thermostat before it starts working.
Best,
Roger