测试目的
为了防止产品因输出超载时产生过高的温度, 直接或间接对人体造
成伤害, 这些伤害有以下几种(电击、能量危险、着火、与热有关的危险、化学
危险);
测试条件:
I/P以额定定电压的上限值,O/P最大额定负载,针对待测物内输出和变压器输出端部份加额外负载,测试待测物及Transformer是否有绝缘破坏或产生火花﹑电击的危险;
测试步骤
首先测试前首先要确定所用仪器设备都在有效期范围内;
先调到额定负载,确定待测样品正常工作;
将待测物中输出和变压器的每组输出,标示清楚,且将记录器的热电耦线粘贴于变压器的coil和core 上;
若有两组以上之直流输出时, 在待测组调至额定值之1.1倍, 其它组则保持定值如下: 例:
将电子负载加载输出端每次一组,且在载入处上加盖一层纱布;
在加载时,须待温度稳定45分钟后再加载,每次加载幅度为10%,直至待测物切断输出;
观察测试中,待测物中的零件或变压器是否有被破坏情形或产生火花引燃纱布的危险;
5.3 |
TABLE: Fault condition tests |
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Ambient temperature (°C) : |
See below |
¾ |
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Power source for EUT: Manufacturer, model/type, output rating : |
HW-050200U7W |
¾ |
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Component |
Fault |
Supply voltage |
Test time |
Fuse # |
Fuse current |
Observation | |||||
5.0V output |
Overload |
240V/ 60Hz |
8.5Hours |
R5 |
0.115→ 0.122→ 0.130→ 0.090→ 0.003 |
Maximum temperature of: T1 Coil= 100.2 degree C T1 Core= 91.7 degree C Ambient= 25.2 degree C Maximum load current was 2.3 A. When increased to 2.5 A unit shut down, Recoverable, NC,NT, NB. | |||||
Supplementary information: |
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Limit of UL60065 is 130-10-10=110K, limit of UL60950-1 is 175 degree C. The temperature chart refer to annex II |