Issue
There is no minimum current listed on the datasheet for Triac outputs on MPx controller.
Product Line
EcoStruxure Buildings Operation
Environment
Building Operation Multi-purpose Controller
Cause
Triac output not correctly switching due to the very small current load.
Resolution
The triac used in an MPx controller will run on low voltage and currents.
In certain circumstances, the current drawn will not be sufficient to keep the triac in the MPx active. This has been seen to be in the region of 10-15 mA.
In this case, a resistor would need to be installed in parallel with the triac to ensure you get a current draw of 20 mA or more for stable operation.
It should also be noted that a Triac output is designed to switch AC load (24 VAC, 0.25 A maximum) and not DC load, refer to: Triac Outputs.
An improved option to the MPx is an RP-C, RP-V or RP-IO, which can switch DC and AC loads with very low current draw, refer to: Solid-state Relay (SSR) Outputs.
