22 Notification Appliances—CH Series Chimes and Strobe Chimes
The peak inrush current waveforms for the CH series chimes and strobe chimes are shown
in Figure 14. Circuit fuses, control devices for the NAC, and power supplies must be
rated to handle this inrush. Current limitations will not prevent the startup unless the
power supply current limiting is achieved by a fast reacting voltage fold-back circuit.
Therefore, if the power supply does not have a fast reacting voltage fold-back circuit, the
power supply ratings can be based on the rated (steady state) current draw. Make sure the
system power supply is compatible with the specified inrush current.
Note:
Inrush current refers to current that exceeds the nominal voltage when the strobe
is first turned on. Once the strobe is turned on, it flashes one flash per second.
Peak current indicates the current rising above the nominal voltage right after
each strobe flash.
!
WARNING:
Personal injury hazard. Ensure all fuses used on NACs are
rated to handle the maximum inrush or peak current from all
devices on the circuit. Failure to do this may result in loss of
power to the NAC and the failure of all devices on that circuit
to operate.
To calculate the maximum inrush or peak current:
1.
Use Table 2 to determine the highest value of rated inrush current or rated peak
current (whichever is higher) for an individual strobe at the expected operating
voltage range of the strobe.
2.
Multiply this value by the total number of strobes on the circuit.
3.
Add the total inrush or peak currents from any other devices on the circuit and
include any required safety factors.
Note:
The time duration of the maximum strobe inrush or peak current is 2
milliseconds for LS, LSM, and MS models, and 4 milliseconds for IS models.
The chime inrush current has a peak value of
0.100 amperes (0.140 amperes for FWR input) with a time constant of 100
milliseconds.
Peak Inrush
Current
