Cisco 7970 Series Phone Manual page 12

Inline power circuits provide current through the communication cable. Use the Cisco
Caution
provided cable or a minimum 24 AWG communication cable.
Warning The power supply must be placed indoors.
Using an External Power Supply
The following warnings apply when you use the external power supply with the Cisco IP Phone:
Warning This product relies on the building's installation for short-circuit (over current)
protection. Ensure that a fuse or circuit breaker no larger than 120 VAC, 15A U.S. (240 VAC,
10A international) is used on the phase conductors (all current-carrying conductors).
Warning The device is designed to work with TN power systems.
Warning The plug-socket combination must be accessible at all times because it serves as the
main disconnecting device.
Only use the Cisco specified power supply with this product.
Caution
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