Boiler house

Level controls

Local regulations may restrict the use of this product to below the conditions quoted.

In the interests of development and improvement of the product, we reserve the right to change the specification without notice. © Copyright 2014

2.3.3

Modulating fill control with high alarm

Using the LC2250 controller

Modulating fill control with low alarm

Modulating empty control with high alarm

Modulating empty control with low alarm

Using the LC2250 controller

On/off fill control with high alarm

On/off fill control with low alarm

On/off empty control with high alarm

(with pump contactor)

On/off empty control with low alarm

(with pump contactor)

Valve modulates to

maintain water level

within this band.

t

Low level alarm

AI-P402-16

AB Issue 6

Tank Level Control

(On/Off or Modulating)

using Capacitance Probes

Description

The system comprises a Spirax Sarco LP20 level probe and PA20 preamplifier together with either an LC2250 controller, and associated

valves and fittings, depending on the application.

Separate literature is available which explains the individual equipment in detail.

Applications

Spirax Sarco capacitance probe based systems can be used to monitor and control the level of a wide range of conductive liquids.

The controllers may be used in a variety of configurations for many different filling or emptying applications.

For modulating level control, Spirax Sarco supply a control valve with an electric actuator and 1000 ohm feedback potentiometer.

The LC2250 level controller should be mounted in a metal or plastic enclosure to provide environmental protection. Spirax Sarco are able

to supply suitable enclosures.

Controllers may be mounted on a 'top hat' DIN rail using the mounting clip provided or the controller base may be screwed directly to a

chassis plate.

If the tank or vessel contents are turbulent the probe should be mounted in a protection tube.

Typical arrangements

The system provides the following options:-

Examples of the many level control duties possible

Control valve

Make-up water

LC2250

OK

LC2250 controller

LP20 probe/

PA20 preamplifier

LC2250

OK

LC2250 controller

AL

AL

Pump

contactor

Condensate return

to boiler house

LP20 probe/

PA20 preamplifier

High level alarm

Pump on

Pump off

Fig. 1

Boiler feedtank make-up with modulating control

and low level alarm.

Fig. 2 Condensate return tank on/off emptying control

with high level alarm

Pump