Call an electrician? (home power)

[Gustav]

Hi all.

I just moved into a new apartment, and I am having a few problems. I am not too fond of the idea of messing with the mains installations, but I'd like to know if I'm being paranoid, or if there is something I can do to check up on things before calling an electrician.

I just set up a few things for my work area, turned on the power and got an awful lot of transformer hum. unplugged everything and proceeded to plug in one thing at a time.

It turned out that a tone generator I was recently gifted was awfully loud (output not plugged into anything, so could only be transformer hum ). I tried a few sockets in the apartment, and in the process, it died.

Same goes for another tone generator I recently "inherited", which also ended up refusing to power on.

These two units have two pole power plugs installed with no ground, but I have never had them plugged in before.

I have a pair of powered speakers that are very loud, but they seem to be staying alive. (3 pin connectors). Soldering station also seems louder, but I am not 100% I am not just "hearing things" at this point.

The first thing I plugged in at the new place was a TV, which would not turn on. I assumed it was broken in transit, but now I am not so sure.

This apartment is an attic turned into an apartment, so the installations are probably "new". I think there might be something that needs looking into, but I don't want to be too paranoid, so - anything I can check? Just call an electrician? Chalk the dead units up to ghosts and see if I can get them working again?

Gustav

 

[pucho812]

if it's an apartment, I would call the land lord and have them deal with it. That is their job plus will keep you from having a law suit if anything were to happen, well at least that's how it goes here in the U.S.  In case of emergency you can dispatch said repair man and then have the land lord reimburse you in the form of less rent that month but again that is how it works in the U.S.

I think part the problem is you have units that you were unsure worked and suspected the electrical when they didn't turn on.
Then add to that you are now over sensitive  to the issue so weather or not there is a problem any little thing gets magnified into a major issue.  I doubt having 2 prong vs 3 prong would make a bit of difference unless the ground was flipped with the neutral  or hot in a junction box which doesn't take much to have that happen but you would see major smoke and stuff coming out of a unit if that were the case. 

 

[keefaz]

If rooms are empty, maybe the various noises can be perceived as louder (room reverb)

 

[[silent:arts]]

If rooms are empty, maybe the various noises can be perceived as louder (room reverb)

This is true. And if the new home is just more quite ...
Never heard the HD inside the DVD player before I moved.

 

[JohnRoberts]

The easiest thing to check is mains voltage (carefully with a VOM). If DK means Denmark I believe you should have 230V-50Hz mains power.

If this mains voltage is unusually high, low,  or distorted it could cause problems with power supplies. 

JR

 

[PRR]

Sounds like 280V on 220V equipment.

How's the incandescent lamps? BRIGHT?

Voltmeter. Carefully!

 

[Gustav]

I opened one of the tone generators that died, and I was fortunate enough to find a fuse inside.

Replaced it with a slow blow, which seems to be better at keeping it alive. That particular unit is still extremely loud, though.

I measured 235VAC off a few sockets in the apartment, so it might be a little high, but I dont really know. Volker and Pucho might be right - a bit of bad luck and different rooms to show the trafo noise higher than usual might have been a bad combo

Gustav

 

[RuudNL]

Here in The Netherlands the mains voltage is 230 V.
In the past I had some problems, caused by a voltage that was too low.
I contacted the company and they explained to me that the tolerance can be as high as 10%
This means that anything between 207 en de 253  V is "normal".
When you measure at different times of the day, you will notice that there are fluctuations.
Sometimes the voltage is a bit higher, sometimes lower than 230 V.
But 235 V is nothing to worry about in my opinion.
The loud sound coming out of the transformers makes me think that the waveform of the AC voltage is not symmetrical.

 

[Speedskater]

[...........................]
The loud sound coming out of the transformers makes me think that the waveform of the AC voltage is not symmetrical.

This is often referred to as DC offset and we see DC blocker circuits. The other cause of this type of hum is a higher line voltage than the transformer was designed for.

 

[PRR]

> But 235 V is nothing to worry about...

Agree.

Out of the abundance of global standards, we have converged to "one" voltage, except half/double depending on local history.

235V to you is 117.5V to me. Often literally: much stuff today is 2-winding transformers, which take half/double voltages according to connection.

Here, 117V is "low OK". I get 250V (125V+125V) from the street. I really don't worry about what I plug in. (When I had a choice, I put 130V lamps in the garage ceiling so I won't have to go up there again soon.)

 

[Gustav]

I havent measured during cooking hours yet, but it seems to be consistent.

However, the amp for my home stereo just died, so I am still a bit on my toes here.

First lamp I put up here blinked - I ended up mounting it in a different outlet, and it was fine.

These things add up! Also, this is my "home town" I moved back to. I remember I used to fry a suspect amount of power transformers in the low end audio gear in my smallish studio set-up until I got a surge protector back then...

Smoke alarms going up today!

Gustav

 

[CJ]

maybe a wandering neutral,  need a scope on there or sure,  be careful,

 

[JohnRoberts]

There are power line loggers that record voltage over time... You need to ping your landlord to ping the power company. If they are killing your gear, they should owe you some compensation.

JR