1. calculation of SCR surface loading density
  SCR surface loading density refers to the power shouldered by one unin surface, density= with the same furnace temperature, the life of rod is shorter as the density is more greater, so don't use SCR overloadedly. Relation of density , furnace loading density. temperature with and surface temperature is as follow: W=5
It is an important way to prolong SCR life that correctly select the surface loading density.
The chart includes the max surface loading density values under different furnace, temperature with nominal using temperature.

2. Selection of SCR dimension calculation of SCR pieces
  Selecting the SCR dimension attention must be paid to the structure of furnace, power and furnace temperature, also to the convenience of wiring and powerdjustment. SCR pieces can be calculated as follow:
pI=F×W(watt) F-surface square per rod W-permitting loaddensity of hotzone necessary pieces:N=×1000 P-furnace power value seres pieces :n= U-end voltage of branch circuit u-voltage per rod

3. Selection of electricity supply and the jointway of SCR
   It is better to select the electricity supply with a wide range of adjustable voltage, such as magna voltage regulator and adjustable silicon control D.C. voltage regurator ect. If leveled voltage regulator is selected, it is better to select the one with smaller level difference and more adjustable grades.
  SCR elements'joint ways can be series and parallel connection ,parallel connection is better. The branch pieces of SCR shouldn't be more than 3 when series connection is used, The joint way and calculation method of common use is in following chart.

1.Before installing you should check the marked resistance value of the cold end,then do arranging the resistances, ensure the difference of every group less than 0.1.

2.When the SCR go through the rodhole on both side of the furnace wall, you should rotate it freely at 360 degree.It is forbidden to install strongly and beat SCR.

3.To use SCR ,you must prepare adjustable voltage regulator or silicon-control voltage regulator、voltage meter current meter and autocontrol temperature meter SCR. In the duration of using, the voltage should be increased to maintain the furnace temperature as normal because the resistance value will go up gradually by oxidation of SCR when the voltage value reaches the uplimit of regulator then the temperature can't meet requirement, you should stop the furnace, change the way of wiring and go on working.

4.When a new furnace is in use, it should work at half of the rated power in case of SCR broken. After everything goes smoothly, the voltage value can be added gradually according to the guidance preventing the SCR from breaking because of too high power.

5.New or long-unused furnaces must be baked before using, it is better to use old SCR or other heating source.

6.Don't use SCR overloadedly. If the SCR break by fault,or the heat radiation is not even, or some part appear whiteheat and dimred, that means SCR has aged asymmetrically and the resistance difference is too high from one segment to another,and so you must check the SCR and replace in the old SCR,you'd better replace all the SCR because partially replacement will result in the unbalanced loading and uneven temperature, the great voltage difference causes the great dufference of SCR temperature, seriously affecting the service life.

7.The SCR should be stored in dry circumstance. If the Al-coated end deteriorates, it can be coated again after surface dressing of used after binding some Al-foil.

8.The SCR is hard and brittle, attention must be paid to transport, openbox, install and replace. Handle with care and don't beat to avoid damage.