Diary PCBuds mini-grow

[PCBuds]

Yeah, ok. The overload welds the timer contact points together (inside the timer) or fuses the electronic timer in no time. Not only do these break and not go off, but the copper strips could start a fire.

In my case, if the timers contacts fuse closed, that just means that my lights stay on but there is no power running through those fused contacts, so no heat, and no risk of fire.

EDIT: If my timers contacts fuse closed, there is 2.5 Watts running through the fused contact or 20 milliamps.


If my timer or its contacts fail, it is not a safety issue, it just stops working.
That's not a big issue for me because I grow Autoflowers and if the lights stay on or don't shut off, it doesn't matter.

 

[exploziv]

I am not so convinced you understand how a modern Switching power supply works. Its basically made to switch on and off in quick succesion.
I have one that is switched on and off for a movement sensor controlled light in a hallway. My guess its it gets 50-100 power cycles a day, some days more. But also, it probably switches on and off for thousand+ a times a second, to save power at low load, for efficiency. Its still there after 2 years, working.
And even if you had to buy a psu once in a while, switching low power AC current is much better and very safe rather than switching high power DC current. A big ass contactor failing should make you rethink this, too. Plus the cost diference in the contactors/ssrs needed to do job for high DC amps rather than low AC amps will quickly eat the new psu "savings". And god forbid it gets to fires. Then for sure you'll regret your decision to protect a psu of some thing it is designed to do up to 10 k times a second, in low load circumstances.
All your examples are valid, but in a time thats far away and with much poorer quality and electronical design equipment.
In those times a dead weight load in a power supply to mantain output on low load was a valid design as well. Now the psu just switches on and off at variable frequency so that it mantains correct output with no energy wasting dead weight loads on it. We are far from those times, man! Don't play with high amps DC power where you don't need to.

 

[PCBuds]

... or fuses the electronic timer in no time.

I'm pretty sure that the SSR's that exploziv mentioned avoids any fire safety issues?

Solid State Relay, not mechanical...

 

[PCBuds]

I am not so convinced you understand how a modern Switching power supply works. Its basically made to switch on and off in quick succesion.
I have one that is switched on and off for a movement sensor controlled light in a hallway. My guess its it gets 50-100 power cycles a day, some days more. But also, it probably switches on and off for thousand+ a times a second, to save power at low load, for efficiency. Its still there after 2 years, working.
And even if you had to buy a psu once in a while, switching low power AC current is much better and very safe rather than switching high power DC current. A big ass contactor failing should make you rethink this, too. Plus the cost diference in the contactors/ssrs needed to do job for high DC amps rather than low AC amps will quickly eat the new psu "savings". And god forbid it gets to fires. Then for sure you'll regret your decision to protect a psu of some thing it is designed to do up to 10 k times a second, in low load circumstances.
All your examples are valid, but in a time thats far away and with much poorer quality and electronical design equipment.
In those times a dead weight load in a power supply to mantain output on low load was a valid design as well. Now the psu just switches on and off at variable frequency so that it mantains correct output with no energy wasting dead weight loads on it. We are far from those times, man! Don't play with high amps DC power where you don't need to.

I am wasted again and will respond tomorrow. Lol

I took pictures though...

 

[f-e]

Solid state does seem a good idea.
The contactor may of failed due to low load. There is nothing to clear the contacts. Had that failed contact had 110vac across it, it may of burnt off the offending oxidation/carbon whatever.
Shame. It did look purposeful. I have never had one fail and have used dozens.

Contactor rating is per pole, but 3 phase, where that power is passed around. To use all 3 single phase, there is a de-rating to be made, for thermal reasons. Perhaps a third. Though this low voltage DC switching, doesn't seem to be working.

 

[PCBuds]

. Though this low voltage DC switching, doesn't seem to be working.

That might be the problem...

I think I'm going to go old school and grow something nasty.

I've got my manually operated contactor picked out...

It's a double pole, double throw switch.

High current low current, high voltage low voltage, AC DC, it always works...


It brought a corpse back to life, it should aughta grow a monster plant. lol

(I'll try to sober up now. lol)

 

[PCBuds]

I checked my thread and my contactor has lasted almost 2 years.

So, that's not too bad.

I'm just going to wire in the new contactor the same way.

I'm just being stubborn about dumb shit that makes no real sense. Lol

 

[PCBuds]

The contactor may of failed due to low load. There is nothing to clear the contacts. Had that failed contact had 110vac across it, it may of burnt off the offending oxidation/carbon whatever.

I just bought this help me refurbish my contactor...

Do you see any problems with coating the contacts with this stuff ??

 

[exploziv]

If you make sure they are tightened well before, no problem.

 

[PCBuds]

She's looking better every day...

 

[PCBuds]

If you make sure they are tightened well before, no problem.

OK, thanks.

I've never had one apart before.
I don't know what I'm in for. I assume it's like a huge relay.

I'm going to wait until my new contactor arrives because I might break this one.

I might have to use a hammer to take it apart. Lol

 

[exploziv]

Oh wait, you mean inside the contactor? Wtf man, no! I though on the contacts you connect the wires to..
A contactor is basically a solenoid that pushes a pin to make a connection between some plates that are connected to thepower source (one side) and load you are switching (second side). It's basically a solenoid operated hi power switch.
If you read on that grease it's an insulator, so it would defeat the purpose of the contactor.

 

[PCBuds]

Yeah, I was thinking inside the contactor for the big contacts...

I'm going to at least clean those contact points.

 

[exploziv]

Use very fine sanding paper (800-1000 grit & up) and do not take off more than needed to clean their surface. Be aware that there may be some hi power springs inside. And also never operate it while open. I actually feel this is a bit over you level, but I have no power over this, if that's your plan, I know you'll do it anyway.

 

[PCBuds]

Actually I've done this sort of thing many times.
I took electronics in school and took all kinds of things apart.

I've actually got a piece of 1,200 grit sandpaper in my wallet to do an emergency repair on the fly. Lol

And I've got a piece beside my toilet.
It works great to remove lime scale.

The muriatic acid can etch the porcelain and the white cloud that rises out of the toilet really burns your eyes. Lol

Hold your breath and run. Lol

 

[PCBuds]

This is my electronics box from 1980...

And the outlet tester we built in 1981...

The teacher jokingly asked one day 'who wants to touch a 700 volt capacitor?'

I volunteered. Lol

My whole arm convulsed.

 

[PCBuds]

She looks really healthy...

And the numbers don't look too bad.

 

[PCBuds]

Oh wait, you mean inside the contactor? Wtf man, no! I though on the contacts you connect the wires to..
A contactor is basically a solenoid that pushes a pin to make a connection between some plates that are connected to thepower source (one side) and load you are switching (second side). It's basically a solenoid operated hi power switch.
If you read on that grease it's an insulator, so it would defeat the purpose of the contactor.

Dielectric grease is silicone grease.
It doesn't conduct electricity and it insulates a contact point from the air so that the contact doesn't oxidize or spark when making contact, but it doesn't prevent the metal contacts from making contact.


Back in the day, TVs had big rotary dial switches and all kinds of mechanical contacts as well as some extremely high voltages.

The switches and contacts were covered in regular grease but the switches were arcing and sparking and burning out.

Then they invented silicone grease (something to do with Roswell I think. Lol) and they realized how good it works at protecting contacts so they sent out repair kits with silicone grease to the TV repair shops to fix all the TVs that were being brought in.



I've got silicone brake grease that I have been using as dielectric grease, but brake grease can have additives in it that may conduct electricity, so I tested my grease with my Ohmeter and it read open line.

I wanted to make sure that I really had the right stuff, so I bought a tube of Dielectric grease today.



They also have contact cleaner tools, but they are expensive...

I made my own tool by gluing 1,200 grit sandpaper to a thin strip of metal from a windshield wiper blade. Lol

As long as it works. Lol

 

[exploziv]

Even if that grease would be great at protecting those surfaces, I'm pretty sure that with the force applied at coupling, it will pretty much taken off the contact surfaces. The danger is that bits of it stay there and catch dust or contaminants and make the contact even worse. If that was a good ideea, they would have did it from the factory.

 

[PCBuds]

Even if that grease would be great at protecting those surfaces, I'm pretty sure that with the force applied at coupling, it will pretty much taken off the contact surfaces. The danger is that bits of it stay there and catch dust or contaminants and make the contact even worse. If that was a good ideea, they would have did it from the factory.

Yeah, that makes sense.
And the force from the contact could splatter the grease.

Oh well, I've got sandpaper. Lol

And contact cleaner.
BTW, MAF sensor cleaner works great as a contact cleaner.

Stuff like brake cleaner can dissolve plastic, but MAF cleaner is safe to spray on a circuit board. (As long as its not plugged in. Lol)