Tekmar 094 and 654, (maybe 680)

Zman

I have a large commercial snowmelt system (~1.5acres) that is acting finicky.
The 3 sensors are 094's (longer cords) and they are controlled by 654's. The 654's report a call for snowmelt to the building automation system that then controls the main boiler plant and some other microsystems.

This setup worked well for 3 years but now it is driving us nuts.
Earlier in the winter, it would call for melt when the sensors were dry. We took it out of automatic and adjusted the calibration. This worked pretty well for a couple of months but now it doesn't call for melt even when the sensors are covered with snow.
The sensors are very clean, so that has been ruled out.

I would like to put a meter on the pucks to verify that the temp, preheat, and moisture sensing functions are working correctly. Tekmar has published this info in the past, but I don't seem to be able to find anything but the temp sensor resistance on their website.

I am also wondering if anyone has experience with the new Tekmar 680 controller with BACnet capability? Does it allow diagnostics and sensitivity adjustments through BACnet or does it just let you see the status?

@Mike_Breault this one is for you
PM me if this info is something that you don't release to the general public.

hot_rod

Zman said:

I have a large commercial snowmelt system (~1.5acres) that is acting finicky.
The 3 sensors are 094's (longer cords) and they are controlled by 654's. The 654's report a call for snowmelt to the building automation system that then controls the main boiler plant and some other microsystems.

This setup worked well for 3 years but now it is driving us nuts.
Earlier in the winter, it would call for melt when the sensors were dry. We took it out of automatic and adjusted the calibration. This worked pretty well for a couple of months but now it doesn't call for melt even when the sensors are covered with snow.
The sensors are very clean, so that has been ruled out.

I would like to put a meter on the pucks to verify that the temp, preheat, and moisture sensing functions are working correctly. Tekmar has published this info in the past, but I don't seem to be able to find anything but the temp sensor resistance on their website.

I am also wondering if anyone has experience with the new Tekmar 680 controller with BACnet capability? Does it allow diagnostics and sensitivity adjustments through BACnet or does it just let you see the status?

@Mike_Breault this one is for you
PM me if this info is something that you don't release to the general public.

Did you try Gregg at Shamrock? He is well versed in those systems.

Gary Jansen_4

Go to the tekmar website, pull up a tekmar 090(094), installation and operation manual. Page 6 shows test procedure for the 090(094) puck. Resistance of the moisture sensor and heater. Black is common. if you can't find it, or need more assistance, call or text me 920 277 0130. or email, garyj@fluidh,com

Regards Gary

Zman

@Gary Jansen_4 Thanks for the info. I was looking at that manual and just missed it. I was panicked for a minute because my truck meter doesn't go to 2M ohms. I just dusted off my Victor 88E shop meter and it will handle the job.

@hot_rod Gregg expects me to give him a headache when I call him. Not sure what he would think if I threw him a softball like that. I probably owe him lunch, that would be a good time to pick his brain about the 680.

Mike_Breault

Sorry for the delay... for some reason tech call have been incredibly busy, and I have been away training. and not onthe wall as much as I should have.

@Zman the IoM for the 090 has been accidently de-listed, and I will get it back, you can find it here tho https://www.pscia.com/ASSETS/DOCUMENTS/ITEMS/EN/tekmar-090-091-manual.pdf

the 680 can be found here https://www.watts.com/products/hvac-hot-water-solutions/controls/snow-melting-controls/680/680

this link is specific to what values are Read or Read write https://www.watts.com/dfsmedia/0533dbba17714b1ab581ab07a4cbb521/81848-source/680-b-03

thisis the IoM https://www.watts.com/dfsmedia/0533dbba17714b1ab581ab07a4cbb521/107029-source/680-d-03

How were the 654 units wired to the BAS? they have no inherent BAS integration so I am assuming it is only sending a Modulation signal to tell the BAS firing / temperature needs, and not a true BAS communications. or are you using a TN4 communications to a 482 gateway? here https://www.watts.com/products/hvac-hot-water-solutions/controls/control-accessories/482/482)

email us at tekmar.customerservice@wattswater.com and we can help you better

Zman

@Mike_Breault
Thanks for the response.
The BAS features in the 680 are awesome.

Mike_Breault

@Zman for a simplified solution, for BAS systems and Snowmelting, look at the NEW 681 BAS interface for the 090/094/095 designed specifically for BAS and launched yesterday

https://www.watts.com/products/hvac-hot-water-solutions/controls/snow-melting-controls/681/681

Zman

@Mike_Breault
That is awesome!
What's retail on that one?

Mike_Breault

@Zman I can only give published MSRP.. but 1716 CDN, 1406 USD