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I took a class about 10 yrs ago which I saw as a product sales pitch.

I see it now. Controlling the outdoor unit Page 157 in my book. Not quite sequence of operation, but thanks.

Can anybody give me a simplified run down on the operation of this unit? I have little to no real knowledge of this unit. I downloaded a 400 page book and see nothing on sequence of operation....

Good idea I'll check

Hey folks,
I'm in commercial work, facility maintenance.
We're about to start predictive maintenance, IR scanning, vibration and sound analysis.
It sounds interesting but do you folks buy into it...

yea..what he said!

R-value79

I completely feel for you man . I was I a similar predicament. For what its worth : Knowing what I know now, I would ask to partner with an experienced tech that has good teaching...

Thanks, I appreciate the response.

I have a question regarding poe oils.
I know that time is critical when handling these oils.
But is there any guidelines available as to exposure and such.
I ask because I recently worked with a...

Point taken........and please, not the boo boo face:gah:

So then you can't go around saying a "ton" of cooling was added to a space due to all the variables that need to be accounted for, is that correct?

No, I don't think he's using a figure of speech. And he's not trying to impress me. He's used that expression in this instance a few times and I just thought it wasn't quite right. I'm not going...

You make an excellent point.

Sorry about the above post error I was trying to combine 2 quotes and I haven't learned that nifty little trick.
Any how when I apply the formula to my situation the btuh comes to 8208 since I am...

400 CFM wouldn't be unusual for a commercial app. A 10" or 12" rd. Sensible heat BTUH=1.08 x CFM x Delta T.Like said, you'd neNot incorrect when you break down the formula... A "ton" is 12k btu.. so...

I guess I should have mentioned that this is an office bldg so it would naturally be a commercial application.
But answer me this then, what if you start delivering the same cfm (400) of say 65 or...

I have a quick question.
My boss likes to say he added about a 'ton' of air conditioning (400 cfm of 55 degree air) to a space, via opening a damper on a vav box.
Is that correct terminology, just...

Yes its true that the sheaves should be replaced, but it's not always done. I guess due to cost. I will put the fixed sheaves on after the v/p sheaves wear out, especially where multi-groove sheaves...

It's hard to say how long belts should last, mainly because of conditions as some have mentioned. But if the alignment is true and the sheave and pulley is not worn you should be able to get a year...

Well, as I mentioned in my post I didn't know for sure if damage could be done.
Our engineer was one who thought the insulation could be broken down. Its good to get as many knowledgable thoughts as...

Glad you asked.

The majority feel theres more harm than good. Windings take a beating during the process. Don't know if its true.

Hi All,

I was wondering what the thoughts are on doing a megger check on your compressors as a P/M procedure. We're having mixed opinions at our shop.
What do you all feel about this?

Please...

Thanks for the input everyone. I am inclined to narrowing that initial chiller start time, but can see the benefits of the delay.

Question to all,
Is there any reason I would want to delay start up of chillers by 15 or 20 minutes each thru the BAS program? For instance after a power outage the lead chiller will start up after...

I always thought the poly filters did a better job. It seemed like more work to me however and I often replaced them with pleats only due to the convenience in changing them.

Hey everyone,
I have multiple size belts on a variety of units at my facility. Most are quality gates or browning. Most are the cogged variety. I guess my question is how long can I expect to get on...

I appreciate the comments.I brought the question up because we recently had a visit by a team of experts hired by the real estate co. that owns our facilty. Their goal was to find and recommend ways...

Let me add these boxes have electric reheat, and of course they are filtered through the AHU.

Anybody have thoughts on changing filters in fan powered vav boxes? If this has been discussed before post the thread please.

Does anyone know if Green buildings have certain setpoint requirements or parameters for zone thermostats ? If so where can I find this information. Reason I ask is, somewhere along the line I heard...

In regards to the above posting , there are two pneumatically controlled butterfly valves in this setup. From what I understand, when the chiller is running in the heat recovery mode the primary 4...

Could someone help me to understand the point of this. Here goes: We have two McQuay heat recovery chillers HSC079. On both units , the leaving condensor water lines start off 10 inches then reduces...

I hope I'm not intruding here but I have a very similar question. I hope Aircooled gets back soon!

I think facilities jobs are good because they are mostly steady hours.
But I also think they are limiting. Dont get me wrong, I do facility work and I cant say I have a command on all the equipment...

I hear what everyone is saying!
One thing is certain, changes have been made and this thing is a mess.
Original specs say this is supposed to be a 25 hp motor installed. Currently I have a 40hp...

Just a little unsolicited advice to anyone thats listening. Learn all you can in this field whenever you can. Don't ever put away your books. At 50+ years of age I'm just getting into aspects of this...

I wonder ,has there been a thread that addresses air balancing ? If so please direct me there. Or at least to a site that can get me started.This is an aspect of our trade that I really want to get...

Just to add to my previous post to those listening.I think I may have to do a duct traverse, but I've never done one. In case you're wondering... this unit has a 40 hp motor rated at 1770 rpm. The...

I'm really new to air balancing. I began a facility job a little over a year ago and want to get into this aspect of HVAC. Lately I've been trying to get my feet wet.Theres a ton I need to get up to...

I checked the info all you guys gave on this post.
Question? Do I use the pf in this calculation or not ?
If so, my new adjusted amp is lower. Which would put me way over whats good.Correct?

You just won the chance to become New Englands next victims

I know for certain that the power company fluctuates.These numbers are good. Thanks retired1 for the calculation. This is the type of information I'm looking for. Generally I know theres not a real...

Point taken!

FollettEngineer
You bring up a good point. I may not have been fully loaded as this is a motor used on a constant volume AHU with a variable pitch sheave.No changes have been made to pitch diameter....

Could someone tell me how to figure out how to find the correct amperage on three phase motor circuit if voltage doesnt match nameplate.
For ex: I checked amps on a unit rated at 23.4amps / 460...

Thanks for the response.
The unit is to be emptied so a new drain line could be installed.
The produce will be stored in a refer truck and put back in on Monday.
Good to know leaving the unit run...

Is it advisable to run a walkin with no load?
The reason I ask is repairs will be done on a unit on a saturday.Will it cause problems to run it empty till monday?

Yes
All of the above.
I really only started getting into seal changeouts recently. Not fun!

Is there a site out there that I can get good info on the whats ,whys and hows of circulating pump seals? Not B&G they dont break anything down!

I need some thoughts on this.
We have an air handler thats designed to deliver 30K cfm.
But we're having problems with noise and drafts.
We had to bypass our speed drive on this unit, so we're...