How to diagnose a Defrost time clock. Wiring and Troubleshooting Included

all right so we start by on l1 and l2 on one 
and n if you have a 120 volt circuit L to be   changed to n in this case we're going to use a 
208 circuit that's the one we're gonna see most   commonly so we're gonna power up Terminal 
one okay there's gonna be a straight shot   it's either gonna come from your power on 
the breaker or if you have your coil wired   through your condensing unit you're gonna take 
power from there so wherever we get a dedicated   208 okay as soon as we get power on there it's 
gonna send power up to the timer motor okay as   soon as this timer motor gets power the time 
clock should start advancing so obviously if   you have power there and you mark your time clock 
and you started doing your troubleshooting you're   marked with a sharpie 15 minutes later the 
thing hasn't moved there 20 minutes later so   it's more noticeable it hasn't moved well you 
know the problem right there okay next we have   a jumper on terminal 2 to terminal 1 so these are 
jumper together okay and then we're sending power   up to here and this is a normally open switch 
or normally closed switch the arm will go open   and close sometimes it's drawn with the contacts 
normally closed so come through here we come to 4 okay whenever four has power three will 
be normally open so we can see it right   here three is normally open this one's drawn 
with the arm as well normally you'll see it   drawn with the other orientation with the 
normally open and normally closed contacts   okay so right now three is open okay three 
and four will never be closed or open at   the same time okay at this point four is 
gonna send power down to evaporate fans so now Terminal four is hot and it's obviously 
going to be hot all the time as long as we   have power coming in so we could draw n here in 
the circuit so right now in this setup foreign   and/or hot through red and blue so if you test it 
across four and n you would get 208 at this point   all right at this point Terminal four would send 
power to the red side or the l1 leg of the fan   motors they're all jumper together as you can see 
them they jumper through here okay and then our l2   side is coming from n so we come off of n onto our 
red wire so this is like a universal switch that   all the manufacturers use you don't need this 
specific one for the coil sometimes you want   the specific one just because of how it mounts to 
the coil but if you're in a pinch a lot of these   are universal they use all the same color code 
red brown and black so at this point and would   send power to terminal C okay so if the coil is 
below 35 Fahrenheit this switch here is closed   okay if it's above 35 the switch will be open 
okay why that's important your fans don't turn   on until the coil gets to 35 Fahrenheit okay so 
we're below 35 if you go to a call and the coils   below 35 it's freezing and the fans aren't turning 
on okay you want to check for power between 4 and   F first if we don't have power at 4 and F you 
start working backwards okay and see why F is   not getting power it's probably this switch 
has failed okay so on this orientation here   our fans working all our Viper fans are working 
the switches on the red to black position for an   F get power ok now when we go into a defrost the 
first thing that's going to happen on a defrost   is the normally closed switch tup here they were 
talking about this arm is actually going to open   so as soon as they defrost starts okay so you 
can set those pins it's every six hours   we'll say anywhere from half an hour to one hour 
usually we'll set it to one hour this arm here   is now going to actually open up like this and pin 
one is now going to come here and it's gonna close   this arm right here so they've drawn this arm 
kind of poorly but this arm here is now going to   close so we now have power on pin three okay so 
this normally open contact now becomes normally   closed as soon as we hit that defrost pin on 
the timer we're going to come through three all right we're gonna feed the bottom 
here or you go right to Terminal three so right now screen and are the only ones that 
should be hot okay the fans will no longer be   working because we've lost power on four why 
we don't want the fans to run during defrost   so obvious to use their steam and there's 
moisture we don't want that all going on the   ceiling so we don't want to push all the steam 
and moisture onto the ceiling and then when the   cooler freezes then you get all the droplets of 
steam on the ceiling and then once they defrost   a big ol all over the floor and it might not 
seem like much but over time it will collect all right so right now and in three are hot so if we 
continue to draw through our n we come through   here we're gonna come through our heat or limit 
switch so all this switch is just say one of the   if anything gets stuck closed and the heaters 
always get power we obviously don't want the   heaters on when we when we have the compressor 
on so we have a heat or limit switch that will   open up and I'll turn off the heaters for us this 
is going to come up through here and we're gonna   feed our h1 so now our h1 is hot and if we look at 
our h2 it's wired directly into N and as we know n   is our l2 so we always have power on here as long 
as we have power up top so now our h1 and h2 the   defrost heaters would turn on you frost o'clock 
I usually set to one hour okay so what happens   now in that one hour is now the coil has gotten 
above 35 Fahrenheit so this switch is no longer   going to be closed and now we use the second side 
of the switch so what happens on this second side   of the switch alright so we're gonna come the 
defrost termination switch okay once we get to   55 Fahrenheit so that is most likely gonna happen 
before one hours up if we have a good coil that's   not collecting a lot of ice if we're clocking a 
lot of ice and we're going to the full cycle the   full one hour that's telling us we probably have 
an issue either a drain or something something's   freezing up there's too much ice or frost on the 
coil could be a TXV adjustment there's all kinds   of reasons why so once we get to 55 Fahrenheit 
we're gonna close this switch okay so this is   our Brown wire Browns going to X okay X is going 
up to X on our defrost clock okay so right here   we show a load here so this guy right here is 
actually a solenoid okay so that's a solenoid   okay so because pin three is hot as well still pin 
three comes over to here okay so as soon as X gets   power and three should be setting power to at all 
times this solenoid activates what this solenoid   does is it activates a plunger okay as soon as the 
plunger goes up and you'll hear it click okay as   soon as the plunger goes up and will remove power 
from 3 and put it back onto four okay why we want   this to happen is what I was talking about earlier 
we don't want too much steam in the box so if once   we get above 55 that's what we found is the number 
of 55 coil temperature not box temperature once   we get to that number we're creating a lot of 
steam in that box and as soon as we get water   droplets on the ceiling and they freeze and then 
once we go back into defrost it'll leak all over   the floor okay and it adds up over time if you do 
it over a couple days or even over a couple even   a week is enough for it to be noticeable on the 
floor obviously once we have water on the floor   it's gonna freeze up we don't have any defrost 
elements under the floor so it literally becomes   a slip-and-fall hazard as soon as this solenoids 
activated we're gonna lose power on three okay and then ii was gonna jumper the power 
back up to for this arms gonna be closed again   because our solenoid activated and activated 
that plunger now that we lost power on three   of the solenoids no longer in the circuit and 
then four comes back down it's gonna feed this   whole circuit again if we have power on terminal 
X here okay you can never be in a defrost so if   you ever using a defrost clock and as soon as 
you put it into defrost right away it's going   back into cooling a lot of people think hey the 
problems with the defrost clock but in fact you   have to come and take a look at this X terminal 
okay because as soon as we have power on this X   terminal we're gonna have power up here on this 
solenoid this is a pretty common problem you're   gonna see is sometimes this arm gets stuck up 
here and I've seen that happen a lot and I've   seen it get stuck both ways actually up and down 
okay but when the arm gets stuck up here what   happens is it thinks the coils 55 Fahrenheit and 
it'll never go into a defrost okay so if you go   and you have a clock and even you'll see it on the 
true timers they have the green light red light if   you go into defrost it goes to red light for 1 
second it clicks off the first thing I'm going   to is this switch okay if there's power on X we 
have power on the solenoid anytime there's power   on the solenoid the plunger kicks up it takes 
3 out it kicks this arm out it closes this arm   right here now we're going to wire we're gonna 
wire in a digital thermostat okay so this one's   a little bit funny the schematic doesn't really 
add up to what they have in the booklet and I'll   I'll show you why so the first thing you want to 
do is L okay that's gonna go to terminal 1 right   here okay we're gonna jumper that in there 
we're gonna send a wire from terminal 1 okay   now whether you have a 208 or 120 volts unit 
okay so we're gonna stick with our 208 we're   gonna come from here and we're going right on 
end so that means we always have power at the   thermostat okay how they've drawn it here is 
they want you to take power from from Terminal   four okay you can't take power from Terminal 
four because as soon as this solenoid they're   sorry as soon as the defrost clocks activated 
Terminal four will lose power and you'll lose   your digital display okay so we're not going 
to use this jumper wire so what we're gonna do   is from LC we're gonna take this we're gonna go 
to terminal 4 okay so that means the only time   the actual contacts okay so this side here is for 
power and for display the only time the contacts   have power is when we're not in a defrost okay 
that's important we don't want the compressor   running during a defrost obviously it defeats the 
purpose okay the compressor will keep running the   fans will keep running and the elements will be 
on alright your ally know is gonna come here and   it's gonna tie into your wire for right here 
so you're not going to connect this wire for   coming out okay and you're gonna connect this 
right into your liquid line solenoid okay so   now we have power on here when these terminals 
close these terminals can only close way up now now if your in ever in a situation like that where 
this switch has failed close if you disconnect   this ex terminal the defrost will work but it'll 
go for the entire duration so if it's set to 30   minutes or one hour it'll go for that length 
so obviously that would be a pretty temporary   solution but at least they would get a defrost 
and the coil won't be freezing up on them second   side is liquid nine solenoid is now gonna get 
power off of N and as we know ends always powered   up that's your l2 ok it's a straight shot it's 
coming from wherever you're coming from either   the contactor for the compressor or front separate 
circuits it's a straight shot from your power feed you

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