Timer for a Schneider Conext SW

MrM1

I was thinking about adding a timer to the AC in side of my CSW inverter.  Problem is I see lots of water heater 240v 30a and 40am timers,  but none of the Philips head screw "lugs" look large enough for the #8 THHN type wire I have used for the AC input of the CSW.    Any thoughts as to a timer that might have big enough lugs for #8 wire?    I was looking at the Tork DTU40 ... but again not sure of the max wire size. 

mike95490

You will have to use a conventional timer to trigger a Contactor relay
 Generally used for motor controls, but I suppose you could use a 40HP version as a beefy disconnect (maybe 15HP is enough, you research what size you need for 80A)
https://www.grainger.com/category/contactors/motor-controls/electrical/ecatalog/N-19s2?searchRedirect=contactor

Timers:  (only up to 40A)
https://www.grainger.com/category/electromechanical-timers/timers/industrial-automation/industrial-controls-automation-and-machine-safety/electrical/ecatalog/N-qgf

MrM1

Thanks Mike

Help me understand and educate me.  Why is a timer by itself not going to work if it is 40a and 240v which is my max load that would come from the AC input into the CSW.  Is it simply because a timer is not made that will take #8 under the lugs,  or is it because the contacts of the switches in the timer would not handle the load being that it is resistive but also inductive.

mcgivor

The Tork timer would work with the load, just #8 would be too large, splice down to #10 solid in a junction box before entering the timer and remember the overcurrent protection will be limited to the smallest conductors #10 so 30A.

http://waterheatertimer.org/How-to-wire-Tork-DTU40-timer.html

MrM1

Thanks,  may do that.   I know it is not good practice,  but would eliminating 2 strands from the #8 so it fits under the lugs be the same as splicing in #10?  

I was looking at the contactors Mike linked - I liked the idea ... but all I was seeing at 4:30am this morning was ones in the $700 plus range?  Was I looking at the wrong ones?

mcgivor

If the contactor route is your choice, search " definite purpose " contactors, and you are correct, it's bad practice ti eliminate strands, furthermore it's not recommended to use stranded conductors on the terminals of the Tork time clock.  Using a contactor will allow the use of a timer with a lower current rating as it will only drive the coil, food for thought.

mike95490

at 40A, timer contacts will eventually give out, a beefy contactor is not likely to fail, they are designed to switch giant currents

mike95490

or get the 40A timer and see how long it lasts - might save the hassle of wiring up a contactor in its own box.

t00ls

found this ...it accepts #8 wire and handles 40 amp loads
https://www.intermatic.com/en/timer-controls/specialty-time-switches/whavq7

MrM1

t00ls said:

found this ...it accepts #8 wire and handles 40 amp loads
https://www.intermatic.com/en/timer-controls/specialty-time-switches/whavq7

Do you have a link or where it is stating it will take #8?  Not seeing it.  But I am just now skimming thru the install sheet

MrM1

Yeah in the install sheet it does not specifically say #8 ... or at least that the connection lugs will fit #8,  it just says yes #8 for 40amp and #10 for 30 amp  in the warning and safety section.  So not sure if that is general fire safety or if that is saying the timer will allow for #8.  Would be nice to see closeup pics.