The main differences between 8.7/10kV and 8.7/15kV lie in their voltage ratings and maximum withstand voltages. 8.7/10kV has a voltage rating of 10kV and a maximum withstand voltage of 12kV; while 8.7/15kV has a voltage rating of 15kV and a maximum withstand voltage of 17.5kV.
1. Differences in Withstand Voltage Ratings
First, regarding withstand voltage ratings, 8.7/10kV and 8.7/15kV cables have different phase-to-phase voltage ratings. The former has a phase-to-phase voltage rating of 10kV, meaning it can withstand a voltage of 10kV between conductors without breakdown; the latter has a phase-to-phase voltage rating of 15kV, offering a higher withstand voltage capability. Therefore, 8.7/15kV cables should be selected for applications requiring higher voltages.
In addition, the maximum system voltage (Um) they can withstand also differs. 8.7/10kV cables can withstand a maximum voltage of 12kV, while 8.7/15kV cables can withstand voltages up to 17.5kV. This difference gives 8.7/15kV cables a wider range of applications in high-voltage transmission systems.
II. Differences in Application Scenarios
Due to their different withstand voltage ratings, the two cables also have different application scenarios. Generally speaking, 8.7/10kV cables are more suitable for power systems rated at 10kV, such as urban distribution networks and internal power supplies for industrial and mining enterprises. 8.7/15kV cables, on the other hand, are suitable for power systems rated at 15kV, such as large industrial plants and inter-regional grid interconnections, requiring long-distance, high-capacity power transmission.
III. Differences in Fault Withstand Time
In terms of fault withstand time, 8.7/10kV cables generally fall into the second category of cables in 10kV systems, characterized by a fault dissipation time exceeding one minute. This means that in the event of a fault, the cable can maintain a certain voltage withstand capacity for a longer period of time, providing maintenance personnel with more time to respond. In contrast, 8.7/15kV cables are classified as Class I cables in the 15kV system, characterized by a fault recovery time of no more than one minute. Therefore, in situations where rapid power restoration is required, such as emergency backup power systems for critical facilities, 8.7/15kV cables may be more suitable.
