Running a large pump via tekmar 356

hot_rod

This tekmar has a 2.4A relay. Has anyone used an isolation relay, like a triac to run larger pumps?

With the Caleffi and many digital solar controllers they have a 1A solid state, trial relay. Any off the shelf 120V triac relay can be wired into that output.

Not sure what type of output you get from the tekmar? Tekmar suggested a 240V circ.

Harvey Ramer

I am anxiously awaiting an answer on this one!

SWEI

The 356 has a TRIAC chopper in it just like many of the solar controllers do. It's chopping up the AC waveform 120 times per second down to about 30% or so, and after that it switches to a PWM algorithm. A mechanical relay won't react fast enough, but a solid state relay might be just fine.

How large a pump are you trying to run? Can you get it with a 3Ø motor? That will perform far better on a VFD (which you can feed with single phase power) than any of those TRIAC speed controls will on a single phase motor.

hot_rod

Here is what we do with the I-solar control, when we need to switch and modulate in excess of 1A.
This is an inexpensive Omron triac relay, 25A in a small box! I've run a 5hp shop vac on this setup.
These triacs are everywhere now a days, this one is commonly used in electric boilers to modulate the elements.

I'll look for a 356 to test this, but I don't think tekmar is willing to bless it , even if it works.

I think the HBX controls will switch closer to 5A in their VS controls, I know they have expanded their offering recently.

BobC

Make sure that is mounted to metal, with thermal compound, so it can dissipate it's internal heat.

Bob

hot_rod

BobC said:

Make sure that is mounted to metal, with thermal compound, so it can dissipate it's internal heat.

Bob

good point, they heat up quickly with the higher loads.