Electrically isolating network hardware from dehumidifier: isolation transformer or line conditioner?

Hi. I have a dehumidifier plugged into the same electrical outlet as my DSL router and wireless router. I want to electrically isolate the DSL and wireless units from the on/off switching of the dehumidifier. The dehumidifier has a big electric motor inside of it, and I've read that the on/off action of that motor kicks electrical garbage backwards into the line and can affect my electronics.

I've narrowed my choices down to either an isolation transformer:

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or a line conditioner:

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The models I picked out cost about the same. It looks like they cover most of the same ground, but not being an electrician, I'm not completely sure. Which do you recommend?

Thanks. Roger Carlson

Reply to
rogacasa
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You most likely do not need any isolation. Your routers have power supplies with big capacitors that will absorb reasonable transients. I lean toward protecting the entire building or home with a transient suppressor at the main power panel.

Reply to
Charles Schuler

it doesn't hurt to put the smallest name-brand UPS you can lay your hands on in front of the DSL modem and router. I was able to use the internet with my laptop for the entire 24 hours of the last big blackout because that's how I was wired.

I had a *big* ups for my desktop system, which I shut down as soon as the power quit. I ran the laptop and the DSL connection off the big UPS for the next day, easily.

Nothing, short of a direct lightning hit, that happens to your DSL router can be propagated to your PC or any other LAN devices.

Reply to
Al Dykes

The isolation xformer won't help. The line conditioner will but you want to plug your electronics into it, not the dehumidifier - this means you can buy a much much smaller line conditioner.

But I would do two things first. 1) See if you actually have a problem. The electronics gear is likely to do just fine without any extra gizmos.

2) See if you can run the dehumidifier from another socket or circuit in the house.
Reply to
Bennett Price

Unless you're seeing a problem, I wouldn't bother. The router should be regulating its own power (and if it runs off of a "wall wart" there's already considerable isolation), and ethernet is designed to be pretty tolerant of noise.

Reply to
CJT

IF YOU HAVE A PROBLEM :

A filter on the offending gear will do more at far less cost than all the gear you hang on the router's power supply.

My electric range was talking to my audio modem (different outlets of course, but parallel wire runs, same electrical service)

No amount of filtering on the phone line or modem supply (external modem) would fix it. For years I had to shut down the modem while cooking. - and I have a lot of experience in the field.

I fixed it by winding a simple choke and putting the choke and a couple of capacitors across the line inside the stove. I had to do it that way because I couldn't find a ready made filter for the stove (too high current)

Try a power line filter on the dehumidifier. Not a "surge suppressor" Surge suppressors are only good for removing damaging power line spikes - L-C , Inductor/capacitor filters take out the hash the surge suppressor won't.

Likewise a simple resistor capacitor "snubber" added across a switch will kill a lot of the noise. 100 ohm 1/2 watt resistor in series with a .1 ufd / 250 volts AC capacitor, wired across the switch contacts in the dehumidifier will stop a lot of hash because it absorbs most of the inductive spark when the switch opens.

An ounce of filtering on the noise generating apparatus will do more than any amount on the noise receiving apparatus.

An isolation transformer is not likely to do much good unless it is "box shielded." A very expensive, but very effective noise eliminating winding technique. The primary and secondary windings both have electrostatic shields around the entire winding. Each shield is insulated, brought out separately, and grounded to different points.

I worked at a power supply manufacterer where we made a few custom wound box shielded transformers - with the amount of effort that goes into one, I'd be surprised to find a production commercial unit for any reasonable cost.

Reply to
default

Hi Roger,

I had a simlar problem with my 3 x PC's at my home, long tern stabilty issues relating to AC supply "noise". An AC Power Filter removed the major part of the noise (spikes, surges, etc) from the line, but not the "short term" (.5 - 2 second) "hits". Plus after 5 years the Power Filter stopped being effective and actually resutlerd in premature failure of 2 x Power supplies in 2 machines util I worked out what was going on..

I then invested in a small UPS and all 3 amchines have been perfect (IE 100%) since then (justover 3 years so far). Yes, I have had AC outages longer than the battery life (~25 mins), but anything less has been 100% convered. I can definately recommend a good small UPS (~500VA capacity per PC). The hard part is sizing the unit for your particular environment.

Good luck...............pk.

Reply to
Peter

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