Ul 489 Vs 1077. When to use ul 489 when to use ul 1077. Ul 489 undergoes more rigorous testing than ul 1077.
Ul 489 versus ul 1077 testing requirements. In contrast supplementary protectors typically have only been tested at 5 000 amperes or less unless a manufacturer requests evaluation at a higher value. According to ul branch circuit overcurrent protective devices are rated for at least 5 000 amperes interrupting rating and are often rated at a much higher level.
Whereas a ul 1077 supplementary protector protects one device except for those that feed motors or.
Notee ul 489 devices can be used in place of ul 1077. Ul 489 undergoes more rigorous testing than ul 1077. Ul 1077 devices cannot be used in place of ul 489. However each motor is protected by a ul1077 supplemental miniature breaker.
