KING GPT 3 User Manual

We manage heat

®

®

Model GPT–3

Freeze Protection Thermostat

Part Number 19425

Installation and Operation Manual

Environmental Technology, Inc.

1850 N Sheridan Street
South Bend, Indiana 46628
[phone] or [phone]
FAX [phone] or [phone]
http://www.networketi.com/

DISCLAIMER

Environmental Technology, Inc. makes no representations or warranties, either expressed or implied,

with respect to the contents of this publication or the products that it describes, and specifically

disclaims any implied warranties of merchantability or fitness for any particular purpose.

Environmental Technology, Inc. reserves the right to revise this publication and to make changes and

improvements to the products described in this publication without the obligation of Environmental

Technology, Inc. to notify any person or organization of such revisions, changes or improvements.

Copyright © 2005 Environmental Technology, Inc. All rights reserved. No part of this manual may be

reproduced or translated in any form or by any means, electronic or mechanical including photocopying

and recording, for any purpose without the express written consent of Environmental Technology, Inc.

The ETI logo, We Manage Heat, Tracon and GPT are reg is tered trademarks of En vi ron men tal

Technology, Inc.

Printed in USA

PN20656 rev 6/2006

Table of Contents

Safety 7

Contacting Environmental Technology 7

General 7

Introduction 7

Specifi cations 9

Operation 10

Normal 10

Abnormal 10

Installation 10

First 10

Next 10

Location 11

Supply and Heater Connections 11

Sensor and Alarm Relay Connections 12

General 12

Temperature Sensors 12

Alarm Relay Contacts 14

Setup 14

Factory Settings 14

Custom Settings 15

General 15

GFEP 15

Mode 15

Current 16

Constant Wattage Heater Mode 16

Maintenance 17

General 17

Troubleshooting 17

Returns 17

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Index of Figures

Figure 1. GPT–3 dimensional drawing 8

Figure 2. GPT–3 wiring diagram 11

Figure 3. Control and monitor sensor connections for self-limiting heaters 12

Figure 4. Control sensor connection for constant wattage heaters 13

Figure 5. Alarm relay connections 13

Figure 6. DIP switch detail 14

Figure 7. Removing electronic assembly from housing 15

Appendix A. GPT–3 dimensional drawing. 18

Appendix B. GPT–3 wiring diagram. 19

Appendix C. Control and monitor sensor connections for self-limiting heaters. 20

Appendix D. Control and monitor sensor connections for constant wattage heaters 21

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Safety

Make all electrical connections in compliance with the National Electric Code (NFPA 70)

and local electrical code. If you have questions concerning the installation or application, contact

Customer Service.

Contacting Environmental Technology

For assistance, contact Customer Service. Office hours are 8:00 AM until 5:00 PM EST

(UTC minus five hours).

Voice: [phone] (USA and Canada) or [phone] (elsewhere)

Fax: [phone] (USA and Canada) or [phone] (elsewhere)

E-mail: [e-mail]

Mail: Environmental Technology, Inc.

1850 North Sheridan Street

South Bend, IN 46628

General

Introduction

The GPT–3 Freeze Protection Thermostat has a calibrated adjustment range of 41° to 77°F

(5° to 25°C) with a control band of 2°F (1°C). Heaters operate at ambient temperatures below the

set temperature.

The GPT–3 combines temperature control using either constant wattage or self-limiting

heaters with GFEP (ground fault equipment protection) and advanced monitoring features. For

example, although the GFEP is factory set to trip at 30 mA, this threshhold can be set to 60,

90 or 120 mA to cure nuisance tripping problems. Keeping wet fire sprinklers from freezing is

considered to be a higher priority than interrupting heater power in the event of a ground fault

condition. The GPT–3 accommodates this requirement by allowing the GFEP to be set only to

alarm while the ground fault persists.

Other features include continuous heater monitoring with separate modes for constant

wattage and self-limiting heaters. A trickle current verifies heater continuity of both heater

types when there is no call for heat. The current flow through constant wattage heaters verifies

continuity during operation. Self-limiting heaters employ an independent temperature monitor

sensor (included) to measure the hot-end temperature. Depending upon how long it takes the

cable to reach its operating temperature such that the monitor sensor is less than 5°F (3°C) below

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