Hazardous Area LT300Ex, Low Tension, Ignition System with Flame Surveillance

The Igniter Control System has been designed to offer maximum reliability and flexibility.  It uses only one Low Tension cable to transmit the spark and also receive the 'Flame On' and 'Igniter Fault' Signal.

100% Discrimination between Main and Pilot Flames Low voltage from Ignition Control Unit to Igniter Analogue Flame Signal Readout

Short Circuit Fault Detection & System Protection Available for use in Zone 1 Hazardous areas.  ATEX Certificate No: CESI 01 ATEX 036, Area Code II 2GD Exd IIC T6

LT300 Ignition Control System

The Igniter Control System was designed to be used in conjunction with a single electrode Gas-Air mix Igniter Rod.  The Igniter Coil is mounted at the rear end of the Igniter Rod, and connections are via a 3-way plug and socket.  The Igniter Coil is fed from a pulse generator, which is switched by a Thyristor.  This pulsed 140VDC supply is applied to the Low Tension winding of the Coil, which in turn generates the high-tension spark.

Operation

Signals required from Control System.

1. 24VDC Signal or a volt free closed contract for 3 seconds (Initiate Spark)

2. Command to open Gas Valve (Timed Process)

During the Spark 'On' period the ionisation detector rejects any signals from the spark generated, this is taken cared of by the capacitor network, thus a 'Flame present' detection signal can only take place once the spark has been removed and a flame on signal from the electrode had been detected.

The flame on signal is achieved by 'Ionisation'.  When a gas flame is established, this permits a positive flow of ions between the electrode and the Igniter head.  This gives a variable forward resistance.  The Igniter Control System has a set resistance threshold and when this threshold is reached the relay in the control system is energised indicated by LED Flame On.  This change is displayed on a 0-10V analogue signal strength meter, which is incorporated into the control system to indicate when the Gas-Air mix is correct.

Specification

Flame off response time 1 second fixed Output 1. Flame On. 1 relay changeover contacts rated 230VAC 1 Amp. Output 2. 140VDC Pulse to Igniter Coil Output 3. Igniter Fault Relay Operating temperature 0-85 C

Input 1. Spark Initiation Volt Free Contact Input 2. Spark Initiation 24VDC Power requirements 115VAC/230VAC 50/60Hz 20VA + 10%-20% Weight 10kg (Zone 1 System)

Gas-Air Pre Mix Igniter

This Igniter, of the Gas Air Mix design, produces a very hard stable gas flame and will light the main fuel under all conditions of combustion airflow.

It is possible to totally discriminate between the Igniter gas flame and main flame by incorporating our Gas Flame Ionisation detection system.

One stainless steel flexible hose is connected to the Igniter for the supply of the Gas/Air mixture from the Credfeld Gas/Air Mixer unit.

The system is connected to a local ignition plate, which provides all the necessary services.  The interconnecting cable terminates in an encapsulated transormer coil on the igniter which provides the energy to produce the ignition spark and thereafter transmitting the ionisation signal to the control unit.

LT300Exs Igniters c/w encapsulated coils