DSH 401 Mains supply transformers: Short Circuit and Overload tests

小米

广东安规检测
有限公司提供：

小型摆管淋雨试验机

IPX5X6X7喷水试验机

1000L恒温恒湿箱

各种试验指现货

可程式恒温恒湿试验箱

水平垂直燃烧机

自动卷线器试验机

耐划痕试验机

各种灯头量规现货

灼热丝试验机现货

GB1002插头量规

IPX1-X7淋雨现货

IEC61347/UL935镇流器热试验箱

灯具防风罩

IK冲击试验机

UL498插头插座量规

VDE0620插头插座量规

稳定性试验台

家电温升测试角

针焰试验机现货

热电偶焊机现货

家电125mm试验指

E12灯头量规

无绳壶无绳电熨斗插拔寿命试验机

IEC60335试验指甲

DSH 401 8 Q  O2 J4 {' n+ I0 M7 }5 B/ i

Mains supply transformers: Short Circuit and Overload tests

57.9.1 1 m; ^/ v. o% r( G" @

60601-1(ed.2);am1;am2

Standard(s)- (year and edition):
( {4 r+ e: A- F# t. l/ T0 ~IEC 60601-1:1988 Ed.2 Am1+Am2
Sub clause(s): 57.9.1
Sheet n°: DSH-401
& m6 P$ ]) L$ [- ?, |" gSubject: Mains supply transformers: Short Circuit and Overload tests
Key words: Over-current, protection, overload
Confirmed by CTL at its 39th meeting, in Cologne
& W* ^$ [" Q1 E. ^Question:
Secondary circuit OVER-CURRENT PROTECTION is the first active component on the
secondary side of a mains supply transformer. Is the overload test performed before or after the
; C3 {- T" F6 ^3 i# M8 Jfuse?
- |) |0 ^7 B/ z% `Insufficient transformer winding crossover insulation and secondary circuit CREEPAGE
DISTANCES and AIR CLEARANCES causes transformer winding to short-circuit and exceed
# T# W3 e5 q1 H  ?& m! {2 fallowable temperatures.
Decision:
If the possibility of a short-circuit exists before the secondary OVER-CURRENT PROTECTION
device (e.g. failure of basic insulation between winding or detachment of the wiring) the short
5 |: r4 b; K$ b! B1 m6 Tcircuit test should be conducted at the exit of the wiring from the transformer.
7 @0 y" k3 N* I(N.B. Similar recommendations can be made for batteries and their protective devices)
: [6 W0 h: c4 z# g$ |The overload test however must always be conducted after any secondary OVER-CURRENT
7 k+ S# S) f* k  K& {; p5 b+ cPROTECTION device (conform clause 57.9.1b) providing that the conditions of sub-clause
57.9.1. second dash are fulfilled.
) r% ^9 N$ J9 q5 u! B3 M. y
+ G# P8 D' w. I3 S# }