Motor start/stop with overload

The brief

Client

Riverside Effluent Works

Site

Transfer pump P-101

Work order

RE-2601

Industry

Water treatment

Task code

PLC-01

Difficulty

Foundation

Type of work

Programming

Write the start/stop control for a single motor: a seal-in, fail-safe stop and emergency stop inputs, an overload trip and two indicator lamps.

What you do

1. Read the client brief and the tag table: 7 tags, 4 inputs and 3 outputs.
2. Write the logic in ladder, Structured Text or SFC.
3. Press Simulate and watch the plant answer your program.
4. Run the factory acceptance test and fix what fails.

Skills you practise

• Seal-in circuits
• Normally closed safety inputs
• Fail-safe stop logic
• Indicator lamps

What the test checks

The factory acceptance test runs 5 numbered tests against your program. The numbers in the brief are drawn per learner. The tests are:

• Start runs the motor and it keeps running
• Stop stops the motor and it stays stopped
• E-stop stops the motor and needs a fresh Start
• An overload trip stops the motor and it does not restart by itself
• Start does nothing while a stop is active

In this lab

• Ladder, Structured Text and SFC in one studio
• A plant that answers: motors, tanks, conveyors
• Numbered tests mark your program