FactoryTalktotheHand
Member
Have a customer asking if they can eliminate a High Limit controller from an electric furnace they're building since we now have PLC controls. This is the high-limit controller they plan on replacing:
https://www.honeywellprocess.com/library/support/Public/Documents/51-52-25-122.pdf
I've been Google searching and can't find anything on any kind of requirement to have a separate high limit controller. It doesn't look like this is a safety device since it's easily programmable. It's probably a good idea from a design standpoint to have it in case of a PLC malfunction, but I can tell them that and they could easily say "we're not worried about that."
Is anyone aware of a regulation requiring a high-limit controller on an electric heating application like this? I could see it on a gas-fired furnace, but electric is a bit of a different animal.
https://www.honeywellprocess.com/library/support/Public/Documents/51-52-25-122.pdf
I've been Google searching and can't find anything on any kind of requirement to have a separate high limit controller. It doesn't look like this is a safety device since it's easily programmable. It's probably a good idea from a design standpoint to have it in case of a PLC malfunction, but I can tell them that and they could easily say "we're not worried about that."
Is anyone aware of a regulation requiring a high-limit controller on an electric heating application like this? I could see it on a gas-fired furnace, but electric is a bit of a different animal.