I've got A project and am looking for ideas. I would like to come up with A circuit that would include A timer which when I start A cooler motor, two fan motor starters will come on, and after the cooler is shut down the two fans will continue to run for A set amount of time using A timer. I know i'll need to latch both starters, just thought I might get some input on the this control circuit.

 

Are you looking to build or buy?

The circuit controlling the fans is called a "delay-on-break" control.

Some manufacturers are:
http://www.artisancontrols.com/timer-modes.htm
http://www.ssac.com/
http://www.accesscontrolsales.com/Airotronics/delayon.htm
http://www.omega.com/pptst/TD-69.html
http://www.airotronics.com/site/timing_delaybreak.php
http://www.icmcontrols.com/products/category.php?cat_pk=11

Ken

 

I'm looking to build the circuit for an existing system its all three phase motors and, I guess I' looking for the simplest way to controll the two fans with probably an hour off delay.

 

I guess by build I was talking about to the: ac-dc power supply, resistors, capacitors, ICs, relay...level. For the cost of one of these modules, it hardly seems worth the effort for a big three phase power control system. D-O-B module plus a maybe a relay or SSR to control the Fan contactors.

But that's just my take....I hate re-inventing a cheap wheel.

Ken

 

Hey thanks Ken for the input

 

Hey Ken If I was going to control the two fan motor starter relays with just standard timers, what kind of setup do you see me configuring
thanks in advance

 

Any chance you have a wiring diagram for your current switching setup. Also, the coil current and voltage rating for the fan contactors? The timer modules make it pretty simple. I would think just one timer module driving one electromechanical or solid state relay that will control the fan contactors.

But as always...the devil's in the details.

Ken

 

Ken I don't have A wiring diagram on hand but the best I can tell you is the coil is 120v with 51 ohms across the coil which would put us at less than 2.5 amps. currently the circuit has A start and stop pushbutton with momentary contacts witch with the start latching the coil. actually I hate to change the scope mid stream on you but this is what I need to come up with. I actually have two coolers and two fans, both coolers are started separately and are powered through AB 1336 plus inverters and the fans which you already know are set up with contactors.

what I want to do is be able to start both fans by starting either cooler and also maintain the independent individual starting of each fan by the present start and stop controls. not forgetting that I need A one hour delay after the fans have been shut off when the coolers are shut down. I know that I have severely changed the scope of things but If you have any ideas I would greatly appreciate it

Thanks alot Alan

 

Alan,

At this point I'm going to jump ship on you. I'm not an industrial electrician or HVAC guru, so the scope of your system has gone beyond what I can visualize...3-phase inverter VFDs and all. Though I'm sure what you want is do-able, anything I would tell you is "more than I know".

I'll be interested to see if anyone else can jump in on this for you.

Good luck,

Ken

 

Hey Ken I appreciate your time and the input you've already provided. I have an Electronics background myself but not nearly as refined as your's. I'm in A position were I've been able to solve problems without involving Engineering, and being resourceful in A pinch can be what keeps you floating, It's great!

I've been an Industrial Electrician for A few years but definitely find myself over my head. learning more and more all the time. and learning is what it's all about

Alan