Just curious, I spotted one in a thread I was reading. Anyone else here in the trade?

Up until last year, I worked for a company in Shoreview that made, among other things, laboratory and hospital room pressure monitors/controllers and fume hood face velocity monitors/controllers.

I'm an electrical engineer, and I was the main EE that developed the circuit boards and control firmware for the devices. I spent A LOT of time in the field overseeing installs and performing calibration on the systems, which involved plenty of HVAC stuff. Pretty neat stuff....we had patented methods for measuring and controlling pressure differential between labs/OR's, such that you could tightly control how negative/positive a particular room's pressure was in reference to an ante-room or hallway.

Over the years, I got to see some crazy shit (goverment bio-level 3 containment labs, morgues, tuberculosis isolation rooms, etc.). We were heavily involved with ASHRAE (my boss was a committee member and wrote a few white papers on various subjects), and we frequently attended the related trade shows, which were always impressive.

I've since left the company and now work for an industrial tool manufacturer. I do miss working in the HVAC field though...I learned A LOT over the years working on that stuff.

Derwood98 - thanks, by the way, for contributing to my thread I started the other day relating to the failed draft blower inducer in my Carrier unit. I was able to find a replacement and swapping it out was pretty easy, and she's running like a charm now.

No problem. I just happen to have an inside with the Carrier product line and was able to pull the part numbers pretty quickly.

So what do you do?

Commercial Refrigeration sales for the local Carrier distributor. I used to be on the contracting side engineering and installing supermarket refrigeration. Now I sell the products to the contractors. A lot less stress.

Hey, maybe you could help me out here. When I was working on the furnace the other day, I noticed that the HSI was very black and charred, leading me to believe that it may fail sooner than later (I replaced it once about 3 years ago, and I know that they do tend to fail every so often).

Based on your post in my other thread, the Carrier p/n for the HSI is "332505-751". From what I can tell from some other distributors, p/n "LH33ZG001" is also a valid p/n. Anyway, I'm looking through my Johnstone catalog, and I found an HSI made by Robertshaw (p/n 41-409), which appears to be cross-referenced with Carrier p/n LH33ZS001A and LH33ZS002. Can you tell me whether or not this Robertshaw p/n would work for a Carrier 58PAV?

Our parts catalog shows p/n 332505-751 as being the only part used on that furnace. The other ones are valid HSI nubers, but not for that furnace. They may or may not work. The best thing to do is get the number off the HSI. That will help to cross it to a Robertshaw or you could just get the OEM replacement.

Based on my searching around, it seems like some of these p/n's represent an 'upgrade' to a silicone-nitride ignitor (as opposed to the traditional silicone-carbide). I guess I'll need to get back into the furnace to record the actual p/n that's on the ignitor that's in there now.

Thanks for the advice...

on a side note, my wife is a technical recruiter who places engineer and HVAC folks...PM me if you are in the market and looking for a gig...I'll send her the details and see if she can help.