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TABLE OF CONTENTS 

 

1.0 GENERAL INFORMATION                                     

1.1 Introduction ...................................................... 4 

1.2 Local Regulations .............................................. 4 

1.3 Recommendations ............................................ 4 

1.3.1 Preventative Maintenance............................. 4 

1.3.2 Water Treatment ........................................... 4 

2.0 STORAGE & HANDLING 

2.1 Receiving .......................................................... 4 

2.2 Storage ............................................................. 4 

2.3 Uncrating .......................................................... 5 

2.4 Placement ......................................................... 5 

Figure 1 -Minimum Clearance ................................. 5 

3.0 INSTALLATION 

3.1 Piping Connections ........................................... 5 

3.2 Electrical Connections ....................................... 6 

3.2.1 Power Feed Wiring ........................................ 6 

3.2.2 Grounding Conductors ................................... 6 

3.2.3 Control Wiring  .............................................. 6 

3.3 Filling the System .............................................. 6 

4.0 PRE-STARTUP INSPECTION 

4.1 Minimum Equipment for Startup ...................... 7 

4.2 Mechanical System Checks ............................... 7 

4.2.1 Plumbing Connections ................................... 7 

4.2.2 Feedpump / Circ Pumps ................................. 7 

4.2.3 System Flush .................................................. 7 

4.2.4 Valves ............................................................ 7 

4.3 Electrical System Checks ................................... 7 

4.4 Heating Elements .............................................. 8 

4.5 Inspection Power / Voltage .............................. 8 

5.0 STARTUP INSTRUCTIONS 

5.1 Control Settings ................................................ 8 

5.1.1 Controller ...................................................... 8 

5.1.2 High Limit ...................................................... 9 

5.1.3 Low Water Cutoffs ......................................... 9 

5.1.4 Low Limit Sensors .......................................... 9 

5.2 Operating Instructions ...................................... 9 

5.2.2 Electric Door Interlocks .................................. 9 

5.2.4 120-Volt Power Source .................................. 9 

5.2.6 Alarm and Reset Circuits ................................ 9 

5.2.7 Sequencing of Element Circuits ...................... 9 

6.0 SEQUENCE OF OPERATION  

6.1 Activation of Heating Element Circuits ........... 10 

6.1.1 Contactors ................................................... 10 

6.1.2 Fuses ........................................................... 10 

6.2 Sequencing Controls ....................................... 10 

6.2.1 Staged Control Circuit .................................. 10 

6.2.2 Proportional Step Controls .......................... 10 

6.2.2.1 Step Control Sequence ............................. 10

 

6.2.2.2 Progressive Sequence Step Controls ......... 10 

6.2.2.3 Linear Sequence Step Controls ................. 10 

6.2.3 Recycle Feature ........................................... 11 

6.2.4 Manual Toggle Switches .............................. 11 

6.2.5 Preheat Switch ............................................ 11 

7.0 OPERATIONAL TESTING  

7.1 Standard Controls........................................... 11 

7.1.1 135-ohm Controllers .................................... 11 

7.1.2 Solid State Controls ..................................... 11 

7.2 Outdoor Reset Controls .................................. 11 

7.2.1 135-ohm Type Outdoor Reset Controls........ 11 

Table 1 – Setting the Temperature

 

Controller ...... 12 

7.2.2 Solid State Dual Reset Controls ................... 12 

8.0 PREVENTATIVE MAINTENANCE 

8.1 General .......................................................... 12 

8.2 Water Treatment  ........................................... 13 

8.3 Electrical System Maintenance ....................... 13 

8.4 Boiler Mechanical System Maintenance ......... 13 

8.5 Element Replacement Procedure  .................. 14 

Table 2 – Feedwater / Boiler Water Properties  ... 14 

 

 

Summary of Contents for HWST

Page 1: ...Installation and Operating Instructions ELECTRIC HOT WATER STEAM BOILERS...

Page 2: ...injury or property damage Read this manual thoroughly and follow the instructions herein The PRECISION Boilers shall be installed according to the procedures detailed in this manual or the Precision...

Page 3: ...2 Operating Instructions 9 5 2 2 Electric Door Interlocks 9 5 2 4 120 Volt Power Source 9 5 2 6 Alarm and Reset Circuits 9 5 2 7 Sequencing of Element Circuits 9 6 0 SEQUENCE OF OPERATION 6 1 Activati...

Page 4: ...f the authorities having jurisdiction 1 3 Recommendations 1 3 1 Preventative Maintenance A Preventative Maintenance Schedule is provided as a recommendation for periodic equipment Inspections Recordin...

Page 5: ...rs are not suitable for placement on combustible flooring 2 4 2 Leave a permanent space for element removal opposite element access panels as shown on the Dimensional Drawing DD and 36 inches opposite...

Page 6: ...ors The unit is equipped with grounding lugs s inside the power panel s The grounding conductors must be installed and sized in accordance with NEC Article 424 14 The recommended size is noted in the...

Page 7: ...fuses Then check the resistance phase to phase for all three phases Make sure that there are no short circuits phase to phase or phase to ground With a megger 500VDC minimum check contactor load side...

Page 8: ...t during the first day of operation the affected element will not be energized allowing the hot water to drive the moisture out at a controlled rate 4 4 3 Removal of Moisture in Element method 2 An al...

Page 9: ...same margin as specified for high limits to be above the controller setting 5 2 Operating Instructions 5 2 1 With the unit s control power ON OFF or ON OFF PREHEAT switch OFF close the main power swi...

Page 10: ...tactor coil circuits 6 2 2 Proportional Step Controls 6 2 2 1 Step Control Sequence The controller senses the unit s water temperature either via 135 ohm device or thermistor or steam pressure either...

Page 11: ...int the step controller should bring on nominally one half of the steps An adjustable proportional band is provided on the controller sensor to enable tuning the unit to system demand 7 1 2 Solid Stat...

Page 12: ...cause an automatic inverse change of 1 F at the control point NOTE Refer to the applicable vendor literature provided on both the setpoint controls and step controls installed in your boiler 8 0 PREV...

Page 13: ...k torque on element flange bolts The acceptable torque range is 10 15 ft lbs CAUTION Do not over tighten elements 8 4 2 Remove and replace any leaking elements or element gaskets Inspect handhole and...

Page 14: ...ement gaskets should be replaced immediately upon leak detection 8 5 1 Adequately tag wire and then remove wires from defective elements 8 5 2 Remove element by removing the four 4 attachment nuts 8 5...

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