TEKMAR 361

Techman

Inside the control is a dip switch, the dip sw is for 30% enable or 10% enable. What is it that is being "enabled" ?

STEVEusaPA

From the manual...
BOILER ENABLE (30% Enable / 10% Enable)
The 361 has a DIP switch that allows for the selection between a 30% boiler enable and a 10% boiler enable. This switch is only functional when the Boiler Sensor DIP switch is set to Return.
In the 30% position, the 361 closes the Boiler contact when the variable speed output exceeds 30%. The Boiler contact remains closed until the variable speed output reduces below 15%. This setting would normally be chosen for low mass boilers (copper fin- tube, etc.), or systems with low thermal mass in the loop between the boiler and the variable speed injection pump.
In the 10% position, the 361 closes the Boiler contact when the variable speed output exceeds 10%. The Boiler contact remains closed until the variable speed output reduces below 5%. This setting is normally chosen for high mass boilers (cast iron, steel fire- tube, etc.), or systems with large thermal mass in the loop between the boiler and the variable speed injection pump.
In order to prevent short cycling, the Boiler contact has a minimum on time, and a minimum off time.

Here's the manual:
http://www.eagle-mt.com/downloads/Tekmar/Tekmar_D361_Mixing_Control_Data.pdf

Techman

Thanks. I've read the manual,but, I guess I don't understand what the word enable means or its effect on the "system". I understand that the dip switch in one position causes the pump motor to something & supply/return sensor locations.I have several of tekmars"Essays" that I still have to read. Tks again.

Those boiler contacts have a minimum on/off time as stated. Do you happen to know what those time cycles are?

SWEI

The Boiler Enable contacts are wired to the gas valve and fire the boiler.

Tim Potter

The way I understand it, when the injection pump ramps up to (30% or 10%) then the control fires the boiler (or enables the boiler to fire). From watching my own 361, & because it has learning capability, I believe other factors are taken into consideration before firing the boiler.