绝缘距离的计算

1
Requirements of Construction - Materials
UL/CSA - Appropriate Insulation System shall be adopted - UL R/C according to UL1446 - Depending on temperature performance requirement of different applications (Class B, Class F…, etc.) - Materials limited to the Insulation System
安規距離計算-1.1 直線及沿面
• 如果導體之間利用絕緣作為阻隔，但是在無法確保兩個不 同物質間之連結性，故其CL/CR的計算方式如下：
• 利用開槽來延伸CR，則X必須大於1 mm，例：
安規距離計算-2 工作電壓決定距
離
AC to DC Product, <=150Vac
• CL： 輸入電壓≦150Vac的產 品，例如輸入為100127Vac，其基準值為：
(400 – 300)/(2.8-2.2) = (360 – 300)/(X-2.2) X = 2.56 ≒ 2.6 Required creepage = 5.2 mm
Requirements of Construction – Insulation (con’d)
Wound Components – Triple-Insulated Wires - Minimum 3 construction layers shall apply for Reinforced Insulation - Passes Annex U tests (Insulated Winding Wires for Use Without Interleaved
B = Additional value from Table 2J(page30), according to the actual peak working voltage
Required clearance = A + B - Example:
1. Equipment rated 100-240 Vac 2. Measured maximum working voltage 600 Vpk A = 4 mm, B = 0.6 mm Determined clearance = 4.6 mm -Exception: If working environment of altitude above 2000 m is specified, Annex G shall be considered.
2.0 1.5+0.1
C-D
Functional
3.61
A-F
Basic
2.40
1.5+0.1 2.0
若兩點間的RMS電壓小於AC INPUT MAX. VOLTAGE,則兩點取 MAX. INPUT VOLTAGE
總結 A.CL要依據以下來確定:
1. 絕緣類型 2. INPUT VOLTAGE RANGE; 3. WORKING VOLTAGE (Vpeak); 4. Pollution Degree;(Delta select Pollution Degree 3.); 5. Altitude;
f (x) (Sa Sc) (Vb Vc) Sc (Va Vc)
例如: Vrms = 280時,沿面距離為 3.0mm.
f (x) (3.2 2.5) (280 250 ) 2.5 (300 250 )
內插法通常定義爲根據”二個已知值估計出中間值”。 線性內插法在二個已知資料點間畫一條直線，新的資料 點就位於這條直線上，具體位置要根據其值與二個端點 之一的接近程度確定。
Requirements of Construction – Insulation (con’d)
Example of Creepage Determination: 1. Measured working voltage = 360 Vrms 2. Pollution Degree 2 3. Material Group II Required creepage distance = 2X From Table 2L:
安規距離計算-5 操作高度與直線距離之關係
• 依據研究及IEC60664-1的規範，越高海拔的大氣壓力 越小，所以必須加長直線距離，用以符合原始所需之 安規要求，如下圖，以海拔10,000英呎(3,048公尺)為例， 最終直線距離CL必須乘上海拔係數1.15倍。
安規距離計算-6 工作電壓決定距離 Creepage (CR): 沿面距離
查表2H,2J及2L取得沿面(CR)及直線距離(CL)
trace
insulation
CR
CL
A-C
Basic
2.88
2.0
C-E
Reinforced
4.76
4.0
B-E
Reห้องสมุดไป่ตู้nforced
6.20
A-B
Basic
2.58
4.0+0.2 2.0
A-D
Basic
2.38
B-C
Funtional
2.40
Insulation) - Where two wires cross each other at an angle between 45˚ - 90˚ , an additional
physical separation shall be provided, e.g. by sheet material.
from core.
- Some considered as primary/secondary all components on opposite side shall keep Reinforced Insulation from core.
Requirements of Construction – Marking
Insulation Requirement According to IEC60950
安規距離計算-1 直線及沿面
• 直線距離：Clearance distance = CL 定義：任何可能之最短路徑，且 CL≦CR。
• 沿面距離：Creepage distance = CR 定義：攀爬物體表面之最短路徑。
6. 計算方法:CL=A+B (A: Minimum value from Table 2H,
according to the mains voltage; B: Additional value from Table 2J, according to the actual peak working voltage,A,B取值應看大)
Company name or trade mark “E115982”
Factory Location - “DCGM” - “DET” - “DEIC” - “DEIT” - “DCWM”
System Designation - “MP-130B” - “MP-130G” - “MP-130I” … etc.
安規距離計算-4 工作電壓決定距 離
DC to DC Product, <=210Vdc
• CL： 輸入≦210Vdc的 DC to DC Converter， 例如輸入為36 to 75Vdc， 則基準值為：
B/I = 1.0mm R/I = 2.0mm； 如右圖： 例：Vdc=96，則 B/I = 1.0 mm R/I = 2.0 mm
45˚ - 90˚
Requirements of Construction – Insulation (con’d)
Core - Usually considered as “floating” all surrounding components shall keep Basic/Supplementary Insulation
B.CR 要依據以下來確定:
1. 絕緣類型; 2. WORKING VOLTAGE (Vrms); 3. Pollution Degree;(Delta select Pollution Degree 2.); 4. Material Group; 5. 計算方法:利用Table 2L已知兩點列直線方程求中間點.
Safety Requirements for Transformers
Construction - Materials - Insulation - Markings Performance - Temperature - Abnormal Tests - Electric Strength Test
Requirements of Construction – Materials (con’d)
Requirements of Construction – Insulation
General – Based on Working Voltage - Clearance: (based on Vpk) A = Minimum value from Table 2H(page29), according to the mains voltage
B/I = 1.0mm R/I = 2.0mm； 若Peak電壓高於210Vpk， 則必須加上其額外值！ 如右圖： 例：Vpk=302，則
B/I = 1.0 + 0.2 = 1.2 mm
R/I = 2.0 + 0.4 = 2.4 mm
安規距離計算-3 工作電壓決定距
離
AC to DC Product, <=300Vac
Other Certifiers – No “Insulation System” requirement - Classification of insulation materials according to IEC 60085 - Material of the lowest temperature rating dominates - UL R/C materials accepted, e.g. tapes, bobbins.