Navitron Renewable Energy and Sustainability Forum

BIOMASS => General => Topic started by: michiel on January 23, 2010, 05:45:19 PM



Title: 3ph timers
Post by: michiel on January 23, 2010, 05:45:19 PM
Does anyone know where I can get a 3ph timer?
A simple 24hr on/of controller, switching a 3ph, 850W pump.

I have spent the last hour ontnet, not found a single unit!

Michiel


Title: Re: 3ph timers
Post by: knighty on January 23, 2010, 05:56:52 PM
just use a single phase one and then a 3 phase contactor ;)


get the contactor from ebay.... it'll be much cheaper !!!
(5ebay vs 90new)

something like THIS (http://cgi.ebay.co.uk/Telemecanique-LC1-D40004U7-Contactor-240v-18-5kw_W0QQitemZ330396059263QQcmdZViewItemQQptZUK_BOI_Industrial_Automation_Control_ET?hash=item4ced23c67f)

it's just like a big relay....

power in at one end, power out at the other

then a negative connection
and a positive conection powered by your timer

:-)


Title: Re: 3ph timers
Post by: johnrae on January 23, 2010, 06:37:28 PM
Bear in mind that, if you use a single phase timer (230 volts) to drive the 3 phase contactor (415 volts), you'll need neutral supply.  The coil on the contactor could be either 415 volts or 230 volts.  If the latter then it'll also need a neutral supply.  Jack


Title: Re: 3ph timers
Post by: michiel on January 23, 2010, 06:50:11 PM
So, if I get a 3ph (415V) contactor with a 230V coil, the Live + Neutral coming from the timer supply the coil.


Title: Re: 3ph timers
Post by: johnrae on January 23, 2010, 07:14:18 PM
you've got it !
jack


Title: Re: 3ph timers
Post by: michiel on January 23, 2010, 07:17:07 PM
Thanks Jack / Knighty

I've already got a timer, so should get job done for under 15. Great

Michiel :)