" Magnetothermal Differential Wall Switch "

Davebones

Senior Member
Have a solvent reclaimer ( Alcohol ) that came in and is manufactured in Italy . It states in the manual that the system MUST be connected thru a Magnetothermal Differential Wall Switch . We are feeding from a 3 phase breaker to a class 1 div 2 disconnect motor rated switch then to the unit . Is this refering to a circuit breaker ?
 

Jraef

Moderator
Staff member
Location
San Francisco Bay Area, CA, USA
Occupation
Electrical Engineer
Have a solvent reclaimer ( Alcohol ) that came in and is manufactured in Italy . It states in the manual that the system MUST be connected thru a Magnetothermal Differential Wall Switch . We are feeding from a 3 phase breaker to a class 1 div 2 disconnect motor rated switch then to the unit . Is this refering to a circuit breaker ?
It might be a translation issue. My mother is Italian and worked for Berlitz (language school) for years. I use to have her translate manuals for Italian machinery for me, but it was always a struggle to re-interpret technical info because a lot of Italian terms, when translated very literally, seem odd to us. "Magnetothermal" does kind of sound like "thermal-magnetic", which would imply a circuit breaker. But the "differential" is a bit odder than usual, not sure what may have been mistranslated to get to that. It might be related to the fact that they don't use the term "on-off" when talking about switches, it is always "open-close", even when discussing a wall switch, but not in the same way we use the terms. for example, "Chiudi la luce" is how they say "Turn off the light", but it literally translates to "Close the light", which would of course be opening the switch. So maybe when they read our codes and saw that a disconnect device is required, their translation of "disconnect switch" became some other term in Italian, which then got re-translated for the manual as "differential". Best thing to do is just ask them for clarification if you can.

Regardless of that, YOU still need to follow OUR codes when installing it, so you will need a circuit breaker (or fuses) in the circuit no matter what.
 

Jraef

Moderator
Staff member
Location
San Francisco Bay Area, CA, USA
Occupation
Electrical Engineer
Talked to my mom, she thinks it is their interpretation of "circuit breaker interrupter switch" from other things she has read. The "wall" may have come about just because someone translating it may have thought that all "switches" are wall switches in the context of electrical equipment, because until she started working with me, she would have thought the exact same thing since her only experience was residential. That sort of thing happens a lot.
 

GoldDigger

Moderator
Staff member
Talked to my mom, she thinks it is their interpretation of "circuit breaker interrupter switch" from other things she has read. The "wall" may have come about just because someone translating it may have thought that all "switches" are wall switches in the context of electrical equipment, because until she started working with me, she would have thought the exact same thing since her only experience was residential. That sort of thing happens a lot.
The differential part might refer to a Residual Current Detector (their similar term function to our GFI). But if that were the case I would expect more words in the translation.

Is there any chance of finding an Italian original on the web?
 

Jraef

Moderator
Staff member
Location
San Francisco Bay Area, CA, USA
Occupation
Electrical Engineer
The differential part might refer to a Residual Current Detector (their similar term function to our GFI). But if that were the case I would expect more words in the translation.

Is there any chance of finding an Italian original on the web?
Oooh, residual / differential, good thought. Might explain the specific reference to magnetothermal. Over there, they can use RCCB's, which are circuit breakers that ONLY do Residual Current protection, but if you ALSO want thermal-magnetic protection, you must use what is called an RCBO, which is an RCCB plus thermal-mag trips. We do not have the equivalent of an RCCB, we would only have what is equivalent to an RCBO.

But also, their code rules for what need GF protection in an installation is very different from our requirements. However if you can find a small enough Electronic Circuit Breaker you can often get Residual Current Equipment Ground Fault protection built-in, that way you are covered.
 
Last edited:

GoldDigger

Moderator
Staff member
Oooh, residual / differential, good thought. Might explain the specific reference to magnetothermal. Over there, they can use RCCB's, which are circuit breakers that ONLY do Residual Current protection, but if you ALSO want thermal-magnetic protection, you must use what is called an RCBO, which is an RCCB plus thermal-mag trips. We do not have the equivalent of an RCCB, we would only have what is equivalent to an RCBO.

But also, their code rules for what need GF protection in an installation is very different from our requirements. However if you can find a small enough Electronic Circuit Breaker you can often get Residual Current Equipment Ground Fault protection built-in, that way you are covered.

I find it interesting that at the receptacle level we have only the GFCI (or AFCI ) which also offers no OCPD.
 

GoldDigger

Moderator
Staff member
Yeah, but in our case, the receptacle circuit would already be protected by a CB up stream, which may be feeding other things besides just that bathroom receptacle.
So, will there often be branch circuits in EU which are protected only against RC at the branch level and rely on the feeder level or main breaker for OCPD?
 
Top