Sprucegrover has giving you the requirments for all, but the voicemail.
You need to have a dedicated 110 outlet with min 15 amp breaker (20 amp recomended). Also do not forget the ground for the phone system is off the third leg of thhe outlet.
From Install manual for MICS:
Electrical requirements
-non-switched outlet within 1.5 m (5 ft.) of the ICS
-The ICS and module power cords are 1.5 m (5 ft.) long.
You may connect the ICS and modules to a power bar. The
power bar must be CSA certified and UL listed with a
third-wire ground.
Do not use an extension cord between the ICS and the
power bar, or between the power bar and the electrical
outlet.
-AC outlet equipped with a third wire safety ground to
provide shock protection and avoid electromagnetic
interference
-dedicated 110 V AC nominal, 50/60 Hz, 15 A minimum
service with a third wire safety ground Risk of electric shock.
The safety of this product requires connection to an
outlet with a third-wire ground. Use only with threeprong
power cord and outlet.
Check ground connections.
Ensure that the electrical ground connections of the
power utility, telephone lines and internal metallic water
pipe system, if present, are connected together. If they
are not connected together, contact the appropriate
electrical inspection authority. Do not attempt to make
the connections yourself.
Good Luck!!