HVAC Low Ambient Control (Pressure Switch)

[TheControlsFreak]

If the unit had some sort of DDC Controls on it the customer could have been alerted of the problem much faster.

***Check out my Blog about HVAC controls to learn more about Building Automation Systems. ***

[theASEtech]

i didn't get what was the problem of the blown fuse can you explain it to me please i'm new on this career trying to learn about a hvac career probably is been a long time since you did this video but i just saw it thanks it is great video

[VanWestComfortHVAC]

@theASEtech I think the refrigerant was migrating to the cooler compressor on the off cycle when the ambient was low (nights & mornings). The compressor may have tried to start against this liquid. The fuse may have blown because of the high amp draw because of this start up situation. I have installed a crank case heater (the wrap around kind) and shall monitor it.

Dave Van West.

[JaydaMaeMae]

Can you please explain the purpose of the air line coming off of the pressure switch where it T's off to the gas valve and the burner box? I don't understand the purpose of this air line going to the gas valve. Even my HVAR instructor can't answer this question, and I'm about Googled to death.

[Straycurrent]

Van - thanks for a very informative video. I see it's been several months since you posted this one, but I hope you don't mind a question now. I see that the fan pressure switch was installed with a tee adapter. I tried one of those once (JB brand), but couldn't get a good seal and was afraid to keep tightening. Do you use them, and if so is there a trick to getting a good seal? I assume it's just brass against brass with no gasket. thanks a lot

[VanWestComfortHVAC]

@Straycurrent Thanks for the question.

I use a blue sealant called "Leak Lok." I apply it ti the male threads. And haven't had a problem. Maybe the specific tee adaptor you used was defective? I have had that happen with Schrader cores in the past.

[dantinas]

Great video. Learned something new...Thanks

[thereceman]

good video.

[dhjr15]

amazing video plz make more for us hvac students that dont pay any attention in class. very helpfull man great job on the video!

[bobbyton80]

Excellent video very well done, I guess you changed the switch?

[VanWestComfortHVAC]

Thanks for the comment. I did not change the switch. I think the refrigerant was migrating to the cooler compressor on the off cycle when the ambient was low (nights & mornings). The compressor may have tried to start against this liquid. The fuse may have blown because of the high amp draw because of this start up situation. I have installed a crank case heater (the wrap around kind) and shall monitor it.

Dave Van West.

[VanWestComfortHVAC]

I use iMovie (Mac) to edit my movies, easy to use, I love it.

I have not used the Hoffman controls, RPM control is better than stop start, by far. Thanks for the tip will look into them!

I proposed a dual mini split for this project.

I did not get the work because I was not the "low bidder" w/ dual mini split system design.

Guess who has the maint agreement? This GUY (thumbs pointing back at my ownself)! Reliability & Efficiency weren't taken into account by the customer when they chose. Thx

[tstatech]

Great video. I just bought a flip cam, so that I can post HVAVR vids. I like the editing what are you using to do that thing at the end?

Ever use Hoffman type low ambiant controls? Varies the RPM instead of shutting it off and on - They still ruin motors.

If I were to design a system for that room, I would use a mini split. Several cool down to 5' F or lower without low ambiant controls.

Awesome video, keep up the good work.