Seminarski rad iz Automatizacije procesa na temu Senzori temperatureFull description
Design-Structural
Labour Output Constant in construction field
Fisica 2Descripción completa
Merise
Descripción: Ver - Sentir - Comprende lo bueno - lo verdadero - lo bello
rise up
rise up
Constant Pressure Booster System
Full description
constant k filters
Adiabatic Temperature Rise Constant The adiabatic temperature rise constant k is the constant term used in the adiabatic temperature rise equation:
2
Where
is the minimum cross-sectional area of the PE conductor (mm ) 2
is the energy of the short circuit ( A s) is the adiabatic temperature rise constant The constant k is made up of the material properties and temperature range of the conductor material (see the derivation of the constant here) here). IEC 60364-5-54 Annex A gives some guidance on the calculation of the constant k, according to the following equation:
o
Where
o
3
is the volumetric heat capacity of the conductor material at 20 C (J/ C mm ) o
o
is the reciprocal of the conductor temperature co efficient of resistivity at 0 C ( C) o is the electrical resistivity of the conductor material at 20 C (Ω mm) and
o
are the conductor initial and final temperatures respectively ( C)
Table of material values Material -
-
Copper
234.5
3.45 x 10
17.241 x 10
Aluminium
228
2.5 x 10
-
28.264 x 10
Lead
230
1.45 x 10
214 x 10
Steel
202
3.8 x 10
-
138 x 10
-
-
-
Table of temperature ranges for conductors not incorporated in cables and not bunched with other cables Insulation o
30
160 or 140(*)
90 C PVC
o
30
160 or 140(*)
90 C Thermosetting
30
250
o
30
200
85 C Rubber
o
30
220
Silicone rubber
30
350
70 C PVC
o
60 C Rubber
(*) For PVC insulated conductors greater than 300mm
2
Table of temperature ranges for bare conductors in contact with cable coverings but not bunched with other cables Cable Covering
PVC
30
200
Polyethylene
30
150
CSP
30
220
Table of temperature ranges for conductors incorporated in cables and bunched with other cables or other insulated conductors Insulation o
70
160 or 140(*)
90 C PVC
o
90
160 or 140(*)
90 C Thermosetting
90
250
60
200
70 C PVC
o
o
60 C Rubber
o
85 C Rubber
85
220
Silicone rubber
180
350
(*) For PVC insulated conductors greater than 300mm
2
Table of temperature ranges for protective conductors as a metallic layer of a cable, e.g. armour, metallic sheath, concentric conductor, etc Insulation o
60
200
90 C PVC
o
80
200
90 C Thermosetting
80
200
o
55
200
85 C Rubber
o
75
220
Mineral PVC covered
70
200
Mineral bare sheathed
105
250
70 C PVC
o
60 C Rubber
Table of temperature ranges for bare conductors with no risk of damaging neighbouring material Conditions
