Package unit with electric heat strips
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- Опубликовано: 27 сен 2024
- In this video we diagnose a rtu at a mall that our customer says isnt heating enough. This rtu is special to me because its equipped with electric heat strips only, no heat pump here guys so its strange for our cold climates. We do some performance checks and clean the unit up a bit. Enjoy
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See a lot of that set up down here in Florida. They maybe complaining because when you have only bank of heat strips you need to move that violet wire on the terminal strip to the orange from the board. This way W1 brings on heat strip with the blower. Otherwise the blower will run with no heat until you get a W2 call. Good vid
Thanks for watching Paul- Appreciate the feedback
Good job bud. Most people don't understand that alot of commercial accounts must be quoted before we can do the work. Or else the company won't get paid. Great video bud.
Thanks Rookie- yeah its a different world dealing with commercial accounts-- I like it when the store manager asks me when Ill be back and I have to explain the invoice goes through 15 people at there corporate office before I can get the approval to return
You make great videos. The way you explain is calmed but you transmit a desire to do the job and do the job right. Thanks.
Thanks Tecnico- I appreciate the positive feedback
you seem like a very honest person
Service tech : The coil is dirty , it needs cleaning .
Customer : why though ?
Service tech : ummm cause it's dirty ...
Customer : I need more reasons
Service tech : dude !
lol- thats exactly right
I tell them it saves them money and show them a chart with numbers to back it up.
Zales 🤦🏽♂️
Tech: “because it’s covered in COVID”
Customer: “OMG”
Tech: “...........I’m tellin ya.”
Customer: “SHUT UP AND TAKE MY MONEY”
🤣
Great tip-of-the-day saving the tie-wrap end!
Yes sir- an old timer taught me that
A common problem is techs hook up the wires color for color. On these Carrier units it is not done this way. Orange to purple and purple to orange. The W1 terminal does not energize the fan. The thermostat energizes the fan. Thermostat must be set up for electric heat. I’m curious if the wire and breaker size were checked for the amp load for the second heat strip. The MOP (maximum over current protection) should be confirmed before adding additional heat.
Thanks
Nice vid. Never seen one in buffalo. Only heat pumps.
Hey RJ- There definitely rare up in my area, especially just strip heat, ive seen a handful of heat pump units with supplemental heat strips but not many of these at all
and thanks for showing me that ohm's law test. I forgot all about that and just the other day I had a heat pump goodman with heat strips. the heat pump was working but the element wasnt. but it was one of those funny things.
I think if this location had a heat pump with the strips a supplemental heat source they would be much better off, not sure who set it up this way or why. For all I know the retail location wasn't part of the original design of this mall, it could have been added on- Thanks for watching
Keep up the good work!! Never thought of doing that with the zips!! We also service some accounts at that mall. Maybe see ya up there one day!
Hey Justin- we might definitely run into each other one day, im there quit a bit now a days- thanks for watchin
I've modified these types of units to become a cheap re-heat by using a humidistat to enable a relay and energize the heat strips while cooling is going to raise the discharge temp and lower the RH in the space
Great 👍🏻 video , I work n a lot of those heat strips it def needs both sides to heat any air , love the tip about the zip tie
Thanks Harry- yeah I agree, they need more heat strips if they wanna stay comfy
Tech tip just blew me away lol. Will definitely try it out from now o
Thanks-
7:44 but is the wiring to the unit sized enough for another bank of heaters?
you should let the owner see how conscientious you are and what a good job you did you would have more work than you can handle..............also for the lay person, if you could show stuff like how you clean the coils etc and suggestions on what the homeowner might use..........................with a disclaimer of course it would be appreciated
RIP- All the ties iv cut off over the years!
Thanks for the tip
lol
Always enjoy the videos, usually only see the straight cool electric heat in areas that don't have natural gas... just curious now but was there a w1/w2 call from stat? Keep posting brother 🙌👊
I think at the time there was a W1 call, I believe at different points, some off camera, I bypassed the stat for a w2 call. If I remember correctly the W1 call initiated the blower and the W2 kicked on the heat strips, sort of a funky set up- just not something I see in my area
uhh there's a problem with your ohms test. There are three heat strips but they're not all wired in series. It's a three-phase supply with two of the phases switched by the contactor and the other always live. Each phase hits one end of a strip, and the other ends of the strips are all tied to each other, kind of a "wye" arrangement but with the center floating... You tested from the black phase to the blue phase, which shows the top and bottom strips to be functional. You did not test the middle strip, which comes back on the yellow wire. Also, note that the black phase is not switched, and your entire test may have been floating at 277V from ground.
Thanks for the feedback, Im going re watch that video and get a better understanding of this WYE pattern you speak of
All of the legs where pulling 14 amps, which makes 9,6 kw at 400 volt. So it verks!
Heat load engineer got to love them
Sure do, lol
Great video. I’ve never seen an RTU with heat strips before (other than in text books), probably because they wouldn’t have sufficient heat output here in Canada.
I have to ask a dumb guy question now...
I saw the (very dirty) condenser coil, but where was the compressor? On the other side of the condenser coil? I’ve worked on a lot of Carrier RTU’s, but not that exact model, maybe it’s different because it’s an electric heat unit. The compressor on the units that I work on is typically right below the electrical panel. Thanks!
Hey 404- not a dumb question, it is in fact on the other side of the condenser, sort of right in the center of it or rather the condenser is sort of wrapped around the compressor if that makes sense-- thanks for watching, I appreciate the feedback
Not to far from me I’m in the Dayton area, I haven’t worked out there yet but I go all over the place
Oh yeah, theres some guys from our company that work out that way-- stay safe out there
thank you partner for sharing!!!!.
Anytime I can bro
10:25 sweeet
Oh yeah
Great explanations
Thanks
Great tech tip !
Hi 5
🙌
is that a variable speed motor. I've notice those looking dirty like that.
Hey Chris- that it is not a variable speed motor, just a plain jane 3 phase motor
👍👍❤❤
Thanks
Cool
Thanks for watching Greg
👍
I worked in Florida lots h/p and electric heat not to much gas.
That's what my buddy Chris at HVACR VIDEOS tells me
@@curioushvacguy6876 it doesnt get too cold for them to use gas or oil so i guess electric and heat pumps would work
Dirty good call
Thanks for watching
Must be big KW
Yes it is
👍👍👍
Thanks
That compressor contactor is smoked.
Your right- I should have added that to my quote, itll be on my spring time pm quote for sure
#73 Thumbs uP
Thanks Steve
Plugo Bugo
For sure- lol thanks for watching
Was the economizer open at all? Was the unit sitting on the curb correctly? I'm a Michigan tech too. I see alot of these Malls that had heat loads taking into effect the Halogen Lights to help heat the store and those tiny bank of heat strips only to tempure the outdoor air intake. Nowadays everybody is switching out the bulbs to LED to save energy and little do they know they got rid of their heat source!
Hey Jason- thats a good point, I didnt even think of that- this Mall Im guessing was built in the 80s maybe so Ill bet the orginal load calc took into account the old light bulbs that acted almost like heating elements, lol--- Thanks for the feedback
Interesting 👍
Jason Southwell now that’s what you call thinking outside the box!
i guess Im randomly asking but does anybody know of a way to log back into an Instagram account..?
I was dumb lost my password. I appreciate any tricks you can offer me!
@Zaid Jaxton Instablaster ;)
A common problem is techs hook up the wires color for color. On these Carrier units it is not done this way. Orange to purple and purple to orange. The W1 terminal does not energize the fan. The thermostat energizes the fan. Thermostat must be set up for electric heat. I’m curious if the wire and breaker size were checked for the amp load for the second heat strip. The MOP (maximum over current protection) should be confirmed before adding additional heat.
Thats a good point- I didnt check the max fuse size or breaker size on this unit-- I go there pretty often so next time Im there im gonna walk on over and take a peak at that compared to the breaker size, im curious now
Thanks AC Tech
Thank you for a learning opportunity. I only watched the first part. Calculations below are "back of the envelope". Any corrections will be appreciated.
Heating elements were not "daisy chained". They were "Wye connected".
Resistance calculation should be done: phase voltage / phase current, i.e. 230/11,5=20 ohm.
You took resistance measurement of two heating elements connected in series, so at service temp. it should be 20+20=40 ohm.
At ambient temperature is should be less, ca. 39 (kanthal).
Jumping thermostat did not prove proper operation of all elements (cabling, thermostat, etc) outside the unit. You mentioned no fact which indicated that the strips were in operation when heat was called by thermostat.
What is the location of heated space? If it has no direct contact to walls/roof/ground, the only need is to heat is the make-up air.
14,3 A indicates 277 V phase voltage. Power should be ca. 14,3 * 277 * 3 = 11,9 kW. 12 kW is roughly equivalent of 36’000 K*m3/h, i.e temperature should increase by 36 Celsius at 1000 m3/h.
Possible scenario: with coil that dirty the flow was much smaller and possibly thermal overloads tripped. The actual power was reduced to a fraction of nominal power. This could have been checked by leaving the heater “on” for a few minutes and observing current.
Also the belt was visibly loose. There’s no way it could pass a test with belt tension gauge.
Damn... I thought he did really well lol
Hey Lutz- thanks for taking the time to explain this, Ill admit electrical theory definitely isn't my strong suit so I have some follow up questions.
You said-
Heating elements were not "daisy chained". They were "Wye connected".
Resistance calculation should be done: phase voltage / phase current, i.e. 230/11,5=20 ohm.
You took resistance measurement of two heating elements connected in series, so at service temp. it should be 20+20=40 ohm.
Can you have elements Wye connected and in a series as well?
On a side note- I did address the loose belt, I didnt show much of it on film after I pulled and cleaned the blower but I adjusted it to appx 1" deflection not using a belt gauge-
As far as the location of the space that is being heated, it is a jewelry store directly below the rtu, 4 walls and a ceiling, and surrounded by other stores. The front of the store has a mostly open design so Im thinking they sized this unit knowing the malls heating system ( Large RTUS that heat the halls, offices, and everywhere else ) would influence and this was just supposed to be used as supplemental heat.
Im still confused how you would go about calculating the amount of amps you should see at the heater bank based on heater size, airflow cfm, return air temp and voltage.
If you care to continue this conversation please shoot me an email at curioushvacguy@gmail.com
Thanks
Aside from taking a supply temp and ensuring you didn't trip the limit, I think this call was well done. We are service techs not electrical engineers. Great job Bill.
@ all major HVAC/R guys on YT I watch carefully your videos and learn from them, e.g. “what’s jumping out at me” is a good start for any job and I learnt it from HVAC*R. I do learn from each of you and am thankful.
Critiquing gives me no pleasure and I can gladly keep all my conclusions to myself. On the other hand I’m not a fan of “safe spaces”, don’t need one and think you don’t need them either.
You can say what you will about military but After Action Report is the best way of self improvement in practical activities. To the best of my abilities to try do just AAR/peer review. Kind regards and Merry Christmas.
Thanks Rookie
That carrier is no spring chicken, I'm wondering why the complaint now? Thanks for the tip.
Hey Brad- thats a good point, I think its because of a management change over. It happens a few times a year where I have to go to these older locations and educate a new manager on what there dealing with as far as aging equipment or funky setups like this
Great video..
Defitinely need a second bank of heat strips..
Your not in south Texas,where 5 kw..is more than enough,with heat pump though..norm here is 7.5 / to 10..
But im sure you need 20- 40 kw of heat im assumimg....
Great tech tip..
Good job cleaning up everything.
Thx for the video..
Bryan Tyler Refrigeration
Thanks Joseph- yeah we dont have Texas Winter temps here, Im guessing you guys have a low of 30 in the winter? That would be nice, lol
Thanks for watching and stay warm down there
@@curioushvacguy6876
Believe or not we have some low 20's and a few oddities of colder.but.yea.mainly low 30 to.upper 20's..
Thanks Bill...
Be safe....Amigo
thanks
Electric heat is about 50/50 with gas heat up here in the northwest. Gas isn't always available especially in rural areas. Energy code pretty much requires most units with electric heat to also have a heat pump capability. Electricity is fairly cheap to very cheap here, and propane is definitely more expensive if that's your only gas option. If you can get the power capacity, zappy zap zap for your warm!
Interesting- thanks for the feedback
Thank you for that at 4:18 didn’t know if that is a way I can check them all at once. I go to a place with 4 rtus with electric heat and this will help a ton lol
And for the record this place complains about the heat to and it does get below 0 here in Illinois
Yeah electric heat strips seem crazy for the low temperatures we see
Straighten out that wonky test lead tip. It's as crooked as a dog's hind.
😎👍
Thanks Shannon, lol- I like a little curve in there--- I actually got a set of new ones but haven't busted them out yet
Heat strips...that must be damn expensive to run!
Does anyone use serpentine belts?
Thats what I was thinking, the electric bill in the winter must be nuts
Resistance goes up with temp!
That has a FUR coat....its keeping warm for the winter
Better then a scarf, lol
Awesome video and thanks 4 the tech tip of the day I'm gonna have to remember that one thanks Curious HVAC much love and keep them videos coming I learn all the time from you and a few other channels I subscribe too. I'm almost done with trades school 4 HVAC one more term to go it's the fourth term Refrigeration application Commercial Refrigeration industrial Refrigeration Energy Efficiency and Green Building standards 1 and 2 and efficiency in Green buildings standard code I can't wait to get the schooling done with to get out into the field and put my skills to use that I've learned in trade School. We go back January 13th then I graduate May 2nd
Hey Grego- thanks for watching and for the positive feedback. Is this a 1 year course your taking? That was my assumption anyway. How do you like the course so far? are they getting in depth about refrigeration theory and circuits and how to troubleshoot? maybe there saving that for the fourth term- good luck bro, stay in touch
@@curioushvacguy6876 this last term we costeucted circuits with motor starters with overloads and alternate relays circuits it's been alot of fun
very cool
I just did a InterTherm trailer with coil elements amazing they use electric here in Michigan
Its not efficient at all, in my opinion, our winters are just to cold- I havent seen to many of these but they are around apparently. What part of Michigan do you service?
Adrian ,Brooklyn, Onsted ,Blissfield and Jackson areas
Awesome - Im right in those areas as well, also detroit and the other side of the state-- what company do you work for if you dont mind me asking?
I work for myself . was in Arizona for 14 years as maintenance supervisor for 5 apartment complexes 2800 units all I did was Ac units .came back to Michigan family issues etc. worked on family and friends units from there word got out and now am to busy
Great video👍👍👍
Thanks for watching
Good video thanks
Thanks Juan
Tip of the day 👍👍
Thanks for watching