Antunes JD-2

SDSteam

Hello!

Completely new to the world of steam and I'm currently training to eventually take over operating & maintaining a central steam plant system. Spent 15 years doing residential and light commercial plumbing and HVAC, so i have experience with hot water systems, just not steam.

I have a ton of questions, but I think I'll start with some easy ones

This is on a low pressure system. We're operating at 9 psi. I know, that's probably way higher than it should be, but that's a discussion for a later (and much longer) thread.

There is an Antunes JD-2 differential switch on the burner of our 750hp boiler. From what I've read, it's simply to assure that the burner is getting enough combustion air. I'm beginning to question the settings on it.

A new burner was installed on our 500hp boiler over the summer. There was an issue on that boiler with the pressure switch tripping and shutting the burner down. It was being starved of air.

If I'm looking at this switch correctly, it appears to be set at 0.1". If so, would that be normal on a 750hp burner? Seems awfully low to me, but I don't have a clue what it should be. Why have a 0.1 - 24" switch and then crank it all the way down? What is a typical setting on a burner like this? JCI burner with a VFD. 1973 Two-pass Kewanee scotch marine boiler. Natural gas.

Also, what's a VFD for on a steam boiler burner?


And don't worry, I'm not adjusting anything. Just trying to gain knowledge right now.