No.7 Switchroom Supporting Design Documentation

Immingham Storage Company Limited – East Terminal

No.3 Pumphouse Modifications – MCC - Basis of Design

P & I Design Ltd

DOCUMENT NO: SI451003_RPT

2 Reed Street, Thornaby, UK, TS17 7AF

ISSUE: A DATE: 07.08.12

Tel: + 44 (0)1642 617444

PAGE 6 OF 7

Fax: + 44 (0)1642 616447

3.4.3

Low Suction Level

A liquid detection probe is installed in the pump suction pipework in order to prove the

presence of liquid and avoid the pump running under dry conditions. It can be the case

however, due to the nature of the company’s business, that the pump will be exposed to dry

suction conditions from time to time due to pipe clearing / tank stripping operations etc.

Override timers are therefore provided to permit short duration dry running if desired. The

control circuit functionality is as follows.

Start Up Override

The probe status is overridden for an adjustable time period after drive energisation via

timer R16T. Once the timer elapses the probe must be covered otherwise the drive will be

stopped.

Running Override

The probe must be uncovered for a time period (adjustable) before the drive is stopped.

This override is provided by R22T

Note : The generic circuit design is based on Exde liquiphant probes. Any variations to this

will be dealt with on an individual basis.

3.4.4

Max Run Timer

This feature has been included based on a request at ISCo West. The timer permits the

drive to run for a maximum period before stopping. This feature is primarily aimed at

manually started and stopped road loading pumps to prevent them being left running

against a dead head at the end of a batch particularly when the pump is remotely located

from the loading point. The timer (R19T) would be set beyond the normal loading period.

If the feature is not required for a particular drive the timer can be set to Max. adjustable

setting or deleted from the circuit.