Alarms for motors

Hi!

I have program to control motors wia scada on slc5/05 AB. Motors is started when the bit START MOTOR is true and input from motor not true then latch the motor. Motor is unlach when the STOP MOTOR bit is true. Next, what I dont know how to do is alarms ladder logic which will energize bit ALARM MOTOR when I start the motor and dont have input response from motor after 2 second.

Any idea?

How about

if you have START MOTOR and dont have MOTOR RUNNING start a 5 sec timer, when timer is done latch on ALARM MOTOR, you could then do an alarm accept from the SCADA that will unlatch this when the above conditions go false.

hope that helps

cheers

myles

I think on this logics, but I have over 20 motors and on scada operator can latch 2 or 3 motor in time less then timer value is set, so I need more condition on the timer.

i meant a seperate alarm for each motor, it would only be one alarm accept from the SCADA. if you need an example of this i could try posting some ladder code, but in the past i have struggled.

cheers

myles

how about this?

Myles - good point about moinitoring to ensure the motor isn't on when it shouldn't be, we learnt that the hard way and burnt out a pump stator! Haven't forgot to do it since!

Thanks for idea.

danijel said:

Thanks for idea.

Click to expand...

No problem, good luck!!

cheers

myles

This is my approach, it is in spanish but it is easy to understand.
Let me explain:
State of motor:
0 = No energy applied to the contactor, aux contact opened, no overload
1 = Energy applied to the contactor, aux contact closed, no overload
2= overload trip
3= if no energy is applied and the aux contact is closed we have a hardware problem, or energy is applied and the aux contact does not close then we have a hardware problem. both of them should last more than 1 second, you can change it to more time if you wanted.
In the scada my approach is to use colors, state 0 is red, state 1 is green, state 2 is red blinking and state 3 is blue or other color you want.
State 2 and 3 are alarms.

that is an other good approch thanks for sharing

cheers

myles