Power Related DDC Issues

[jogas]

I have seen more power related controller failures, lockups, corrupted databases lately than ever before. We've use MOV's on the controller's 24VAC power terminals to help against spikes in the past.
But I am wondering if anyone has found a proven cost-effective protection device that has helped prevent or reduce this problem.
jogas

[chesehd]

What we've done before in problemetic locations is take a UPS and feed a transformer from that.

That way the boards are protected from over/undervoltages, generator tests and other fluctuations.

Seems to work well enough. No need to buy the big, super-duty UPS. Just the basics are sufficient.

Ken

[freddy-b]

What we've done before in problemetic locations is take a UPS and feed a transformer from that.

That way the boards are protected from over/undervoltages, generator tests and other fluctuations.

Seems to work well enough. No need to buy the big, super-duty UPS. Just the basics are sufficient.

Ken

Some even have a fault output....if you can spare a BI on your controller.
Here is a example.http://www.solaheviduty.com/products/ups/sdu.htm

[Chris_Worthington]

We had one job about 9 months ago where something bad happened, 52 LON devices and a Jace taken out all in one big bang :eek:

That sucked !!! all FX LON and "NO" lon cards available for a few weeks :eek:

Now we have started playing around with some stuff to help protect not only the Jace, but the bus as well. The only problem is, its tuff to know what actually works without something bad actually happening :rolleyes:

It sorta sucks to pay for the cost of the part and the labor to install it, when your not even sure if it works...

Anyone else using something to protect whatever bus?

[jogas]

Thanks guys.
I'll look into them.
jogas

[freddy-b]

Optical isolators, running fiber modems thru known problem areas. Thats about all I know that works.

I have seen some jobs where the local ALC dealer has put pico's on their comm. Don't know if that works well? I highly doubt it.

[jogas]

We had one job about 9 months ago where something bad happened, 52 LON devices and a Jace taken out all in one big bang :eek:

That sucked !!! all FX LON and "NO" lon cards available for a few weeks :eek:

Now we have started playing around with some stuff to help protect not only the Jace, but the bus as well. The only problem is, its tuff to know what actually works without something bad actually happening :rolleyes:

It sorta sucks to pay for the cost of the part and the labor to install it, when your not even sure if it works...

Anyone else using something to protect whatever bus?

I was thinking this issue will change the way I lay out my power to each main panel (JACE or whatever), and all of it's devices. Instead of grabbing a dedicated 120VAC circuit from a nearby panel where convenient, just source all panel/device power (24VAC) from a single "protected" source at the main panel and send out to each device. A long time ago, I saw a small Staefa job (1 NCRS, 20 SM2 VAV controllers) laid out this way. All power was sourced, and fused from the main panel. Didn't like it at the time, but it's beginning to make sense now.
While reading at the above Sola site, I saw the STC Data Protection device that looked interesting.
They were talking about POE, Power Over Ethernet. Is anyone using this strategy to power devices? Can it be done with the Products we use? This sounds appealing if acceptable to site IT Departments.

[joey791]

Optical isolators, running fiber modems thru known problem areas. Thats about all I know that works.

I have seen some jobs where the local ALC dealer has put pico's on their comm. Don't know if that works well? I highly doubt it.

Actually the company we rep used to but pico fuses on their comm buses and then replaced them with automatic resetting polyswitch. I have changed a few pico fuses but hadnt really had issues.

Straight power problems I have seen in older buildings where they dont have that good of grounds in the building

[phxurs]

Surge Diverters
Power Filters
Line or Power Conditioners
Uninterruptible Power Supplies (UPS)

I would Isolate – ck's to DDC from other EQ,....and have Dedicated ck's brought in....also Up size all control transformers! Wires / etc, (except fuses) and Check every ground!

[makeitwork]

I use UPS on my main controllers, and isolate with repeaters from panel. From the sound of losing all of the VAV's plus controller, you may have had a spike on the Lon side. If a repeater would have been used in this case the damage would have been limited to inside/outside the panel.

[chesehd]

Has anyone used these for isolating the RS-485?

http://www.edcosurge.com/products/telecom/pc642.asp

They would seem to work well for preventing large spikes on the comm bus from getting too far down the line, depending on how many are installed and where.