Precision HWST Installation And Operating Instructions Manual Download Page 14

14 

 

Water treatment is required for satisfactory operation of steam boilers to prevent both deposition of scale and 
corrosion from acids, oxygen and other harmful elements that may be in the water supply.  A qualified water 
treatment specialist should be consulted to establish a proper water treatment program

 

8.5   Element Replacement Procedure (4-Bolt Style Element) 

 

CAUTION:

  Before element replacement, make certain main power to the unit is turned off, that there is no 

pressure in the unit, and that the unit is drained below the element opening. 
 

NOTE:

  To prevent hazardous conditions of leaking water / steam at the element terminal ends, defective 

elements or element 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

8.5.3

   Install replacement element with the new gasket and torque nuts to 10 -15 ft. lbs

 
 

WARNING:

  Do not exceed 15 ft. lbs. 

 

 

8.5.4

   Connect phase wires to new element. 

8.5.5

   When the unit is filled and pressurized, check for leaks. 

 

Table 2 

Recommended Feedwater and Boiler Water Properties 

FEEDWATER 

Type 

of 

Boiler 

Hardness (ppm) 

pH 

Oxygen 

(cc/l) 

TDS 

(ppm) 

Total Dissolved 

Solids 

Hot Water 

0 – 10 

7.5 – 9.5 

4.0 

0 – 500 

Steam 

0 – 5 

7.5 – 9 

.03 

0 – 350 

BOILER WATER 

Type 

of 

Boiler 

Hardness (ppm) 

pH 

Oxygen 

(cc/l) 

TDS 

(ppm) 

Total Dissolved 

Solids 

Hot Water 

0 – 10 

7.5 – 9.5# 

0 – 5000 

Steam 

7.5 – 9.5# 

0 – 3500 

# - The limit of 9.5 pertains to copper elements; a pH of 10.5 is allowable for Incoloy elements. 

 

 

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...

Reviews: