[SBE] Phasor current draw

[David R. Wilson]

Part of the question ought to be what is the current / voltage ratings
for the contacts on the remote control?  A 30 amp capable relay without
proper interfacing may at best chew up relay contacts on the remote
control pretty quickly (if it works at all). 

As far as the required ratings for the relays, you would need to know
what current they are switching.  If it is switching a 50 ohm non
reactive load, 30 amp contacts should be more than enough.  If it is a
different load it might not be appropriate.  

Dave

David R. Wilson KU4B
Engineer for the Cromwell Group
Nashville Tennessee
WBUZ WPRT WQZQ
615 399 1029 studio
615 579 3177 cell
615 869 9244 cell
615 459 0678 house




On Mon, 2009-07-13 at 16:36 -0400, Edwin Bukont wrote:

> The TPO is 5. My main concern is the total draw of the contactor coils

> during switching.

>  

> Thanks

> 

> Edwin Bukont CSRE, DRB, CBNT 

> V- 240.417.2475; F- 240.368.1265 

> 

>  

> 

> 

> 

> 

>  

> > Date: Mon, 13 Jul 2009 16:16:04 -0400

> > From: ednixon at yahoo.com

> > To: sbe at sbe.org

> > CC: 

> > Subject: Re: [SBE] Phasor current draw

> > 

> > What power levels ?

> > 

> > --- Original Message ---

> > From:"Edwin Bukont" <ebukont at msn.com>

> > Sent:Mon 7/13/09 1:11 pm

> > To:"sbe" <sbe at sbe.org>

> > Subj:[SBE] Phasor current draw

> > 

> > 

> > I am trying to create a DA/NDA remote control for a 3-tower phasor

> system. The system has remote for choosing transmitters and Day or

> Nite. It does not have remote for choosing DA/NDA.

> > 

> > 

> > 

> > Currently, someone has brought out the Tx and D/N to 240VAC relays

> with 30A contacts. Is this really necessary?

> > 

> > 

> > 

> > The mode change itself appears to throw maybe 5 contactors including

> the towers. I realize that in the DA mode it has to support the

> current involved with switching of Day and Night.

> > 

> > 

> > 

> > I want to do my additional control with a 24VDC coil and contacts

> rated at 15A/250VAC.

> > 

> > 

> > 

> > Am I missing something here. Do I really need those big power relays

> or will something smaller suffice. I do not know what the current draw

> is,,and it would be difficult to amp clamp.

> > 

> > 

> > 

> > Anybody have any ideas what a 30-40 year old three tower, 3 modes

> Phasor array might draw in Amps at 250VAC during switching?

> > 

> > 

> > 

> > Thanks

> > 

> > Edwin Bukont CSRE, DRB, CBNT 

> > V- 240.417.2475; F- 240.368.1265 

> > 

> > 

> > 

> > _______________________________________________

> > The SBE Roundtable, SBE at sbe.org

> > To unsubscribe, go to http://seven.pairlist.net/mailman/options/sbe

> > 

> > http://seven.pairlist.net/mailman/listinfo/sbe

> > 

> > _______________________________________________

> > The SBE Roundtable, SBE at sbe.org

> > To unsubscribe, go to http://seven.pairlist.net/mailman/options/sbe

> > 

> > http://seven.pairlist.net/mailman/listinfo/sbe

> _______________________________________________

> The SBE Roundtable, SBE at sbe.org

> To unsubscribe, go to http://seven.pairlist.net/mailman/options/sbe

> 

> http://seven.pairlist.net/mailman/listinfo/sbe