Hi Could you please tell me which one is better electronics or mechanical time r? I want a timer for my basement dehumidifier to turn it on/off for 3-4hrs /day. I saw some timers and I was thinking about mechanical because I do no t have to change battery etc since I might not be around to change the batt ery. I have found this one from Lowes
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But if you think electronics one is better and it can last working for 1 ye ar without changing the battery then I will consider electronics timer.
timer? I want a timer for my basement dehumidifier to turn it on/off for 3-
4hrs/day. I saw some timers and I was thinking about mechanical because I d o not have to change battery etc since I might not be around to change the battery. I have found this one from Lowes
1 year without changing the battery then I will consider electronics timer.
There may be some electronic timers that use a battery to maintain the clock for long periods with power loss, but agree, the one's I've seen don't use batteries. Bigger issue is if the timer is rated for just lights or motor loads like the dehumidifier. All the mechanical ones probably are. The electronic ones, I'd suspect many are not. If it were me, I'd just go with the mechanical. Simple, easy and it works. Just programming the damn electronic ones can be a PIA.
One drawback to a mechanical time is it loses track of time if the power goes off. That wouldn't really matter if you don't care what time the dehumidifier starts and stops.
I use it to charge a spare car battery in my boiler room. I have a 6 amp trickle charger connected to a spare car battery, and the trickle charger is plugged into my timer. Every day at 3:00 PM the timer provides power to the trickle charger for 10 minutes. I've had car batteries die on me in the past without any warning, so I keep a spare battery charged and ready to go.
I like the electronic timers better than the mechanical ones for several reasons:
With a mechanical timer, you're "ON" time can't be less than 15 to 20 minutes or so because of the size of the trippers. Normally, that's not a problem, but in my case it was. I was concerned about overcharging the battery, and so I wanted to be able to have the "ON" time as short as possible. My timer has a minimum "ON" time of one minute.
I was also a bit concerned about having to replace batteries, but the timer I bought (for .00 at a Cargo Surplus store here in Winnipeg) has a built in rechargeable battery. It charges itself off the same power it switches. So, you never have to change the batteries in it, and it'll still display the time and it's programmed settings for several days after you unplug it.
I didn't have a clock in my boiler room. The electronic timer displays the time of day, and so that's a handy feature to have in a room which otherwise wouldn't have a clock.
timer? I want a timer for my basement dehumidifier to turn it on/off for 3
-4hrs/day. I saw some timers and I was thinking about mechanical because I do not have to change battery etc since I might not be around to change the battery. I have found this one from Lowes
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Rvw But if you think electronics one is better and it can last working for
1 year without changing the battery then I will consider electronics timer. Thanks a lot.
I would definitely prefer a mechanical timer. They don't fail (usually) if there is any sort of power surge due to lightning or other things. They d o have to be reset if there is a power failure and you want the on-off to o ccur at a specific time. But for a general x hours on and y hours off, the mechanical timer is definitely my choice.
I don't like the thought of an electronic, and some don't have battery. If power goes off, not sure what happens. I use mechanical like that. Rigging it up, it's easy to push in on the buttons, but once plugged in, it's easy to set up. Just make sure it handles compressor currents ok.
I got a dehumidifier running in 2/2 hour mode, but that's a built in feature of the dehumidifier. It would run continuously otherwise, even set at 70%. .
I service electrical and electronic equipment and when I install new or replace a failed mechanical timer, I'll install an electronic timer every time. The important thing is to use a high quality commercial or industrial timer. I've replaced too many mechanical timers that failed because the mechanical components wear out. The little clock motor wears out and they are replaceable but if a mechanical timer is old enough for the motor to wear out, the mechanical parts are trashed too. For light duty use by a homeowner and I mean light duty, a mechanical timer would be simple to use but if it's going to be used 24/7-365, go with an electronic timer especially if it's used for safety lighting. There is a hybrid timer I like and it uses a clock mechanism like the electronic analog clocks that use a single AA battery. The load switching is done by a heavy duty relay not a mechanical pawl and micro switch which are the most common points of failure in mechanical timers. ^_^
A well-made mechanical timer, meaning its motor spins around rather than go es back and forth (escapement). Some awful timers have motors that do the latter, like one sold by Harbor Freight, and they don't seem to be reliable .
Whatever you get, be sure it's actually safety approved by UL, CSA, TUV, or ETL, to protect you against electric shock and fire (you don't want plasti c that burns). And verify that the safety approval is for real because som e are not, like the one for a Wet Circuits brand power strips (UL issued a press release about that).
My good VCR, that cost $500 30 years ago, had a "memory capacitor", a little bigger than a nickel, that remembered everything for a long time. They sell them separately, for less than $5, that I would have happily paid, at least they used to, but I'm not clever enough to know where in the circuit to install one. (Maybe some circuits would drain the cap so fast it wouldn't be useful?)
But my friend's $100 VCR would forget everything in a power failure and even my $300 Philips or Magnavox DVDR will forget which shows I want to record, although it remembers which channels there are in my channel list (I wish it were the other way around.)
Yes, it doesn't matter when dehumidifying is done** unless the electric company charges more at some times of day. But the user is bound to notice if there was a power failure of any length, and she can reset the clock. If the power failure is only 5 minutes, there is no need to reset the clock.
**For the most part, but the only humidity problem would be if it ran for 2 hours than right after that ran for 2 hours again, when there wasn't enough humidity left to be worth it. But how could that happen with a mechanical timer. Instead the next cycle would be delayed as long as the power was out, not hastened.
***About 1950, my mother had fridge with a self-defrosting freezer. However it never defrosted at the right time. That's because she didn't read the instructions, and she set its clock for the time she WANTED it to defrost, when it was supposed to be set for the current time (and it would defrost at 2 in the morning.) So because she did the time setting at various times, the defrost time jumped all around the clock. By the time I read the instructions, she was moving and selling the fridge iirc.
if there is any sort of power surge due to lightning or other things. The y do have to be reset if there is a power failure and you want the on-off t o occur at a specific time. But for a general x hours on and y hours off, the mechanical timer is definitely my choice.
Why would it matter what time the fridge did the defrost cycle? I've never seen one that had a clock you set.
Probably none. I would much prefer determining time. The top freezer air gets into the 20's during defrost, I've seen. If your opening the thing up during this time, it's much worse. How many times I'm home with groceries, and the thing is on defrost. The bottom fridge, door closed, fairs better. I've data logged a couple units.
She wanted it to defrost in the middle of the night, and indeed it was built to do that. Had she set the clock for the current time, it would have defrosted at 2 or maybe it was 3 or 4AM. Once a day.
This was probably a Crosley Shelvador. made about 1950..
AFAICR the clock was not in the freezer compartment of the fridge, but more likely it was behind a panel on the bottom, was about 4x4" or
4x6" big, with a knob rather than hands, but a clock face behind the knob.
Shelvador does not relate to Shelvador Dali but to the fact that it was one of the first to have shelves on the door, eventuallly putting twice as much food on the front line.
I see you can still buy one from 1952, restored, for $3200.
FWIW, my mother grew up with an ice box, and in the hot weather would catch the guy on the ice wagon so he would give her and her friends ice chips to suck on. Then she went through the stage where you had to defrost the freezer, and she was very happy when we got this around
1950.
There was no fan blowing air out of the freezer. That didn't start afaik until "frost-free" was invented, and iiuc, it's the fan that makes it frost-free.
No, it's not the fan that makes the fridge "frost free".
It's the fact that the place where the refrigerant gets injected as a high pressure liquid and evaporates into a vapour, absorbing heat as it does, was moved from channels molded into the freezer compartment to a special "evaporator coil" typically located in the back wall of the freezer compartment.
And, that evaporator coil was accompanied by a defrost heater, defrost termination switch, defrost timer, defrost pan with drain and a hose that carried the melt water down to the bottom of the fridge where it would re-evaporate into the ambient air. Together, all those parts would automatically defrost the evaporator coil once a day or so so the homeowner didn't have to defrost it.
And, of course, they added an evaporator fan to suck cold air through that evaporator coil and blow it into the freezer compartment, and from there some of the cold air would get sucked back over the evaporator coil and some would get blown down into the fresh food section of the fridge, keeping that space cool, too.
So, a frost free fridge operates on the same thermodynamic cycle that a regular manual defrost fridge does... it's just that it's equipped with all of the necessary equipment to defrost itself every 10 to 20 hours or so. And that defrost cycle is governed by the defrost "timer", which is the "Brains" of a frost free fridge.
Keep this in mind: All frost free fridges that I know of have the compressor and evaporator fan in parallel, with both in series with the thermostat. The other circuit in the fridge will have the defrost heater in series with the defrost thermostat (aka: defrost termination switch). The defrost timer DIVERTS power from the thermostat to the defrost heater for about 20 minutes once every 20 hours or so. That means that when the defrost timer is in defrost mode, power won't be going to the thermostat, and hence not the compressor and evaporator fan either. So, when the fridge is in defrost mode, you should NOT hear the compressor running nor feel a breeze in the freezer compartment. When the defrost cycle is over, then BOTH the compressor and evaporator fan will always come on and go off simultaneously. So, if you hear the compressor running, but there's no breeze in the freezer compartment, there's something wrong with the evaporator fan. Similarily, if you feel a breeze in the freezer compartment, but you can't hear the compressor running, there's something wrong with the compressor.
If the fridge appears to be spending too much time in defrost mode, it could be that the defrost timer is stuck in defrost mode. Defrost timers will be equipped with an exposed output shaft that can be turned to advance the timer manually, putting the fridge back into "run" mode. That shaft will be designed so that it can only be turned in one direction with a slot screw driver. That's because turning that shaft backward can wreck the defrost timer. Unfortunately, the defrost timer will be located in different places on each fridge, so you have to know where yours is before you can turn that output shaft and advance the timer to get the fridge out of defrost mode.
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