Order of Power Management

[Anti-Hero]

Hello

I just finished moving into a new workshop and I have bought some power Conditioning hardware because the AC Line sits at around 107-108, I'm just not sure in which order they should go, I bought a Tripp Lite LC1800 Power Conditioner to bring the AC line to a stable 120VAC, I bought a Tripp Lite IS1000 Isolation Transformer for my variac, and I have a ART PB 4x4 1800 watt power distribution rack bar.

I was thinking

Power Conditioner>Isolation Transformer>ART Power Distribution

Thanks guys

[Anti-Hero]

no one can tell me if i should isolate then condition or condition then isolate?

[Enzo]

It has never been an issue here. Your setup is fancier than mine. I have a power conditioner at home on my computer. An old Tripp something or other, 600 watt, I think.

Think about the job each piece does. Your iso is there to isolate the Unit Under Test, or UUT. So there is no point in running a lot of other stuff through it. We are not too concerned about isolating the shop bench lites for example. The iso is rated at the mains voltage, so I would plug the variac into the iso, not the other way around.

What needs conditioning? Most modern bench gear is not particularly sensitive to mains voltage. The actual supplies inside are regulated. it would only be in times the mains dipped so low that the raw supplies to those regulators dropped out of regulation. I doubt that happens much. And soldering gear? DOn't need conditioning there.

Power distribution is just that. It turns one outlet into several, and it adds on/off switches. SO one switch can control a bunch of stuff. SO how many outlets are there on the LC1800? 5? 22? (I should know this, I used to sell Tripp power stuff in my store) OK< I looked, it has 6. SO it is already a sort of distribution systm. WHat is your intended purpose for the ART unit? If you have one outlet for your bench, then plug the ART into the wall, and the LC1800 into the ART. The remaining ART outlets can power outlet strips for your bench stuff like lites and solder, wall warts and chargers, test gear that doesn;t need fancy power. Then your conditioned power can feed whatever needs it.

SOme guys want to iso their scope and test gear and plug the UUT into the wall. I don;t like that, since then if I refernce my scope ground to for example -170VDC in a switcher, then the entire frame of the scope is at -170VDC with respect to earth ground. In my shop, the iso is for the UUT. Now you mention the iso is for your variac. I have to say me too, I almost never use the iso without using the variac at the same time. Now, since the iso is feeding the variac circuit, why does it need conditioned power? The variac will be dialing in whatever voltage you want anyway, so why tie up a conditioned outlet, and why sap any of the LC1800 power capacity. If that is not an issue for you, then fine, but it could be a consideration. So for me, plug the iso into the wall or the ART, leave the LC1800 for other loads.

SO iso-condition or condition-iso? Neither. Unless I have compelling reasons, I'd not bother running the iso/variac through the conditioner.

[Steve Conner]

I use this gadget. It's a 2 amp variac and 500VA isolating transformer mounted in a wooden crate. The isolating transformer is pemanently wired to the output of the variac, and it's switchable to give 0-270V out, or 0-130 at 4 amps. (We have 240 volt mains here.)

I must get round to making a volt and amp meter for it.

I've also got a larger 10 amp variac and isolating transformer, but I haven't used them in ages. The small one is enough for bringing stuff up and testing it at low power.

I've never used power conditioners. I think they're kind of pointless. If your line voltage meets the national spec, then any equipment that doesn't work is badly designed. If your line voltage doesn't meet the spec, then the power company should fix it. If you want to test equipment at some exact line voltage, then that's what the variac is for.