Motor pump starter connection with two relay to operate manual and auto

[dattlara76]

Hi,
The ckt as as draw as attached, is a auto/manual control panel board for pump-motor and trying to configure to run with MCU control auto operation and manual (with start/stop button in board).
With the panel here i have included 2 nos relay: Relay-1, NO, parallel connected to START BUTTON and Relay-2, NC, series connected with STOP BUTTON for the purpose.
From the ckt, my perception is as follows:
1) Manual operation is found to be correctly.
2) For the case of auto operation: when relay-1 close, the loop of the COIL (CONTRACTOR) closed through Relay-2 and the COIL(CONTRACTOR) is energized, "R" is given to load-motor.
BUT the STARTING CAPACITOR not getting supply through Terminal-C2 of the START button in this arrangement of Auto mode. Then how "Y" will be provided to Motor..

Therefore my question is,
1) Is this connection is correct for the operation without that of starting capacitor arrangement??
2) If not How should I connect to provide phase to STARTING CAPACITOR to keep manual/auto both operation?

Thks..

 

[dattlara76]

hello,
is there anybody help me out with my above issue??

 

[KlausST]

Hi,

Honestly... I don't understand the wiring.
* What's the red box and the green box?
* Where is the motor?

Klaus

 

[dattlara76]

Green and Red are NO and NC Contact Push Button Switch and Motor is at R-Y-B point

Hi,
sorry for ckt is not like ckt as it to be..But please treat the details as follows:

GREEN BOX:
C1 and C2 > NO contact of a push button switch, and

S1 and S2> is another NO contact of a push button switch.


RED BOX::
Red colored is a NC contact the push button switch.

MOTOR::
is at terminal connector 'R' - 'Y' - 'B' terminal point.


where 'P' and 'N' is supply i/p terminal point.

Tnk you..

 

[KlausST]

Hi,

sorry for ckt is not like ckt as it to be..But please treat the details as follows:

The benefit of standard symbols is that it avoids confusion.
Is it more simple to insert a picture with a red box than inserting a symol of a switch?

As far as I can see:
* starting with the green button should work
* stopping with the red button should work
* stopping with the relay should work

But starting with the relay is different, because it does not enable the starting capacitor.

Klaus

 

[dattlara76]

But starting with the relay is different, because it does not enable the starting capacitor.

what arrangement should i maintained to enable starting capacitor at start instead of using two pole relay...
tnx

 

[KlausST]

Hi

instead of using two pole relay

You may use another single pole relay..

Klaus

 

[dattlara76]

You may use another single pole relay..

R U asking for one more PCB Type relay OR to replace what i have already shown SPDT?

I have had google but not find particular model, in which my one can be replaced, would u please let me know about that particular model?

tnx

 

[FvM]

Double pole PCB relays are surely available, you should however talk about current rating. The original manual circuit has the disadvantage that the push button switches have to carry the full motor current, including inrush. You need heavy switches (or restrict operation to a small motor) for reliable operation.

Manual control circuits with push buttons are preferably designed in a way that the push buttons have to run only contactor coil current.

 

[dattlara76]

hi,
The ckt will be use with 2hp/3hp/5hp motor(submersible pump) And pcb relay SPDT of 30A(T90 model).

The original manual circuit has the disadvantage that the push button switches have to carry the full motor current, including inrush.

How push button carry full load current?
I presume,
when GREEN Button pressed, contactor coil current flow path: S1-S2-c(at relay2)-NC(at relay2)-red button-finally at coil. And
Motor current from P to Contractor (shown as thick red line).
That means, motor Load/inrush not going through neither relay/s nor push button/s olny through thick red line as in pic.
If my presumption is correct then 6A rated pcb type miniature relay can be used.
Would you please clear my concept if i am wrong..

tnx for ur reply