Can I use this contactor to switch 11kW/3* 16A, 230/400VAC 50Hz? - Page 1
Forum section: electronics / projects

author: Greybeard
author_rank: Frequent Contributor
timestamp: September 17, 2025, 10:52:52 am
content: Can I use this contactor to switch11kW(3* 16A, 230/400VAC 50Hz) for plug-in hybrid car charger?I couldn't find a datasheet for this exact type (ESB 24-40-00).What does "AC 3:4kW/ 3 ~400V" mean?What's the driver coil voltage (230V AC DC)? Can I use 230VAC to drive this contactor?Do I need a spark suppressor circuit on the driver coil, if I switch the contactor with a timer relay contact?

author: themadhippy
author_rank: Super Contributor
timestamp: September 17, 2025, 11:00:56 am
content: QuoteAC* is the type of load,AC1 is resistive,AC3 is squirrel cage motorsQuotelooks that way

author: rogerggbr
author_rank: Contributor
timestamp: September 17, 2025, 11:22:13 am
content: You can (as above).Datasheethttps://www.farnell.com/datasheets/2906894.pdf

author: Greybeard
author_rank: Frequent Contributor
timestamp: September 17, 2025, 11:31:29 am
content: Quote from: rogerggbr on September 17, 2025, 11:22:13 amThis Datasheet is labeled "ESB 24-40-230AC/DC".I don't know if this datasheet can be used for my ESB 24-40-00The contactor has four poles.Should I use the fourth pole to switch the neutral wire (N)?

author: themadhippy
author_rank: Super Contributor
timestamp: September 17, 2025, 11:54:34 am
content: Quoteyep,looking at the data sheet its shown as having 4 main contacts so all the contacts are suitable rated

author: Greybeard
author_rank: Frequent Contributor
timestamp: September 17, 2025, 02:05:58 pm
content: Quote from: themadhippy on September 17, 2025, 11:54:34 amYes, I know.My question is whether I should switch the neutral wire or just loop it through.

author: themadhippy
author_rank: Super Contributor
timestamp: September 17, 2025, 02:37:41 pm
content: QuoteAnd my answer was yep,the extra bit was to say all 4 contacts are suitable rated. Its not unusual for the 4th contact to be an auxiliary contact for the control circuit and only rated for an amp or 2 . As for switching the neutral ,often its a requirement to switch all current carrying conductors,and the neutral is classed as a current carrying conductor most of the time.

author: Greybeard
author_rank: Frequent Contributor
timestamp: September 17, 2025, 05:26:46 pm
content: I found some info that N contacts have to close first before the 3 phase contacts, and open after the 3 phase contacts.I'm not sure if this conrtactor will do so...I think I will do it this way:https://www.eevblog.com/forum/projects/looking-for-recommendation-for-timers-for-din-top-hat-rail-mounting-(230400v~)/msg6040795/#msg6040795

author: themadhippy
author_rank: Super Contributor
timestamp: September 17, 2025, 07:27:56 pm
content: QuoteWere did that come from? Its something i dont think ive ever come across,earth yes,but neutral?

author: Zero999
author_rank: Super Contributor
timestamp: September 18, 2025, 06:51:07 pm
content: Quote from: themadhippy on September 17, 2025, 07:27:56 pmI think it's better if the neutral is switched first, but the earth should never be switched.

author: Greybeard
author_rank: Frequent Contributor
timestamp: September 18, 2025, 10:52:00 pm
content: As I understood, it's due to the possibility of an asymmetrical load on the three phase lines.If you disconnect the neutral contact before the phase contacts, one phase can experience anovervoltage.Same result if you connect the phase contacts before the neutral contact.V1=V2=V3=230*1.41=324VpR1>R2=R3V(L1)-V(X)> 324Vp(!!!)That's why...Quote from: Greybeard on September 17, 2025, 05:26:46 pmThis should not be a problem if all 4 contactor contacts switch at exactly same time, but the real world is not ideal (mechanical contact tolerances and random fluctuations in switching timing).But I don't know how relevant the phenomenon really is.To rule out the possible problem, I will not switch the neutral wire but rather loop through.Quote from: themadhippy on September 17, 2025, 07:27:56 pmhttps://www.fingers-welt.de/phpBB/viewtopic.php?t=21356https://www.elektrikforen.de/threads/n-ueber-schuetz-mit-abschalten-ja-oder-nein.17025