Eclipse ThermJet TJ0015 - 2000 Technical Information

Contents

Eclipse ThermJet TJ0015 - 2000 Technical Information Manual pdf 7 page image

7ThermJet, V2, Technical Information, Edition 2.14Step 2: Control Methodology■ If the burner is shut off during operation attemperatures above 1000°F (538°C), provisionsmust be made to provide an adequate amount offlowing combustion air to keep the burner internalcomponents cool.The control methodology is the basis for the rest of thedesign process. Once it is known what the system will looklike, the components that are in it can be selected. Thecontrol methodology chosen depends on the type ofprocess to be controlled.NOTE: The stated operational characteristics only apply ifthe described control circuits are followed. Use of differentcontrol methods will result in unknown operationalperformance characteristics. Use the control circuitscontained within this section or contact Eclipse for written,approved alternatives.There are two main methods to control the input of aThermJet system. Each of these methods also has twovariants. These methods may be applied to single burneras well as multiple burner systems.The methods and variants are:1. Modulating control:a. Modulating gas & air, on-ratio control or excess air@ low fire on page 8.b. Modulating gas with fixed-air control on page 9.2. High/low control:a. High/low air & gas control (pulse firing) on page10.b. High/low gas with fixed-air control (Can also beused for pulse firing) on page 11.NOTE: Use of a ratio regulator in a fixed-air system isoptional. However, eliminating the ratio regulator willadversely affect the ignition reliability at inputs greaterthan 40% of maximum.Use of a ratio regulator in a fixed-air system also providesautomatic gas modulation if system air flow changes overtime (such as a clogged air filter).In the pages that follow you will find schematics of thesecontrol methods. The symbols in the schematics areexplained in the “Key to System Schematics” (seeAppendix).Automatic Gas Shut-Off by Burner orShut-Off by ZoneThe automatic gas shut-off valve can be installed in twooperational modes:1. Automatic Gas Shut-Off by BurnerIf the flame monitoring system detects a failure, thegas shut-off valves close the gas supply to the burnerthat caused the failure.2. Automatic Gas Shut-Off by ZoneIf the flame monitoring system detects a failure, thegas shut-off valves close the gas supply to all theburners in the zone that caused the failure.NOTE: All ThermJet control schematics on the followingpages reflect a single gas automatic shut-off valve. Thismay be changed to conform to local safety and/orinsurance requirements. (Refer to the ThermJetInstallation Guide No. 205).NOTICE