Hey guys i need some help with my electric furnace. It is an old Carrier AC/Heat combo. My problem is my heat just never seems to get very warm.
I have checked the elements and they are all 11 ohms. The elements all have voltage to them and there is voltage coming in and out of all the element limit switchs. I don't see how my heat tempature is so low when all the elements are on. The elements are pulling the same amps also. Could the elements be so clogged with dirt that the heat doesn't radiat out?
The sequencer should be alright since the elements are getting voltage shouldn't they. When the unit is on the sequencer terminals all have voltage. There is a terminal that doesn't have voltage. One terminal has 24V and the other terminal has 0 volts on the sequencer and the resistance on this is 60 ohms. There is a symbol between these terminals that looks like a potentiometer symbol.
The obvious stuff has been checked filter, registers, etc.
could be undersized how many kw? how many elements? approx 20 amps per 5 kw so if you have 4- 5kw elements you would expect to see it pulling around 80 amps. is it a heat pump? need more info here
how the air discharging into the space chance you might be running hi or medium speed there instead of low for heating.check you air in/out temp.split on the heater.
All the sequencer pretty much is are contacts if there is voltage to one side of the contact and coming out the other its working. That is the contact itself.
In 1997 I worked on a unit on the north side of the city. The reason I bring this up is the paramedics had just left with the man who worked on it before me. He had 20years in the trade and made a fatal mistake. Skill is important when working with deadly potential difference you cannot see hear or smell.
He also sead the elements are all drawing the same amprage. That means they are all operating. Possably the voltage is low causing less heat. I assume this is a recent problem with a system that has been in place for a wile. This must be a new problem maby the reversing valve has failed in the heat pump and it is acting back like a a/c.
Your elec is very likely to be pulling 240, which is why you are getting 120 twice. There are usually two 120 lines coming into the air handler, i'm not saying you don't have any skill with measuring current, but a hit from 240 will leave you waking up in the next room or not at all, so be super careful.
Take a good thermometer, or a temp probe from your meter, it may have come with it....the small sturdy gold colored wire works great as a temp probe.
When the system kicks on observe the temp, after about 3-4 min watch to see if it increases. You could have a bad reversing valve or thermostat in which you could have the A/C running in "HEAT" and the elec strips are compensating.
Or you could have the unit thinking it's in "DEFROST" mode in which the A/C will be on also and happening like this every cycle.
If you are getting 85 deg or so off the coils alone that's not bad, if it's less then it could be undercharged. The fact your strips are kicking on everytime isn't a factor of how hot they are, it's that they are always kicking on, shouldn't happen unless the stat calls for it because it's not being satisified or it's in defrost mode.
Check your filters, make sure the coils are clean, open all the registers.
Thank you i6pwr I completely understand what your saying about being careful. I deal with this everyday at work except its only 480V:laughing:. Oh wait I was just in a massive layoff thanks to the 2nd great depression so I guess I wont be dealing with 480V anytime soon.
measure voltage at each end of the element, if you have 240give or take there than take an amp reading if you have 240 and no amperage the element or fusable link is bad. or just wait about five minutes for all the seq. to cycle on and amp the incoming power wire
Up until Friday I was a multi craft maintenance tech for a tier 1 supplier to Ford, GM, Nissan, and Toyota. If you've ever seen the news talk about the auto companies while they show video robots welding or carrying parts thats what I took care of. That and whatever else pnuematic, hydraulic, electrical, PLC's, just no HVAC:laughing:.
Its my first whack at the HVAC bit. Its not that bad heck with some training I may actually fix something. I took one of the panels off and a schematic was about to fall off so I grabbed it and it literally crumbled in my hand. I thought great that is going to be a big help. An old outdated unit with half of a schematic. There is some small blue box that has been added to the unit. I have no idea what it is its not shown on the schematic or at least the half that I still have.
back to my original question how many elements and how many amps is the system pulling just snap your amprobe around one of the main power wires inside the furnace assumeing you only have one supply wire
i just reread your original post seems as though all the elements are working based on you stating they all have amperage
have you checked the a/c coil to see if its clogged with dirt? how bout the squirrill cage
no chance theres a fire damper mounted above the furnace is there? although you wouldnt have any airflow and since you didnt mention that ill assume thats ok
is this thing a heat pump or strait electric heat
This is electric no heat pump. I found two elements that were intermittent. Still even when all the elements were on and drawing amperage which was 20 amps each there was little heat. There are three elements. I have plenty of air flow just not much heat. The unit pulls just over 60 amps total.
its probably undersized 15kw is only a little over 51,000 btu and if your in the part of the country thats really cold right now thats why it is acting up now look into slowing the fan down to make the heat warmer red is the color of the slowest fan speed see if its not being used and swap it with whatever wire the fan is running on now
you mentioned intermittant elements if there cycleing on the limits the limits could be weak you could bypass the limits and see if that helps and if so replace them
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Related Threads
?
?
?
?
?
DIY Home Improvement Forum
3.1M posts
319.5K members
Since 2003
A forum community dedicated to Do it yourself-ers and home improvement enthusiasts. Come join the discussion about tools, projects, builds, styles, scales, reviews, accessories, classifieds, and more! Helping You to Do It Yourself!