... can be changed without opening meter, convenient to use, dust proof. Under the same secondary current, scale-change can be conducted ... without loss of accuracy or damaging the meter (48×48 model ... 25A 30A 40A 50A 60A 75A 100A, for 10A-10KA use external current transformer with secondary current 5ANotes: For 60A, 75A, 100A meters, when ...