Tank filling pump

The brief

Client

Harbour Steam Plant

Site

Boiler feed tank T-201

Work order

HS-2605

Industry

Power and utilities

Task code

PLC-05

Difficulty

Foundation

Type of work

Programming

Fill a tank between two level switches without chattering, protect the pump from running dry, and latch an overflow alarm that needs acknowledging.

What you do

1. Read the client brief and the tag table: 7 tags, 5 inputs and 2 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

• Latch and unlatch (OTL/OTU)
• Level control with hysteresis
• Dry-run protection
• Latched alarms and acknowledgement

What the test checks

The factory acceptance test runs 4 numbered tests against your program. The numbers in the brief are drawn per learner. The tests are:

• Fills from the low switch to the high switch and rests in between
• Never runs with the sump dry
• High-high stops the pump and latches the alarm
• Ack clears the alarm only after the level has dropped

In this lab

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