2-12
Main system supply (MSS), continued
MSS
specifications
Table 2-14 lists the specifications for the MSS.
Note: 1. The MSS detects a low or missing AC input and switches to batteries automatically. The system
returns to AC when it detects the presence of acceptable AC levels for a minimum of 30 seconds. AC
wiring must run from a dedicated AC branch circuit, and the breaker/wiring must be sized according
to local codes.
2. When it is necessary to activate large numbers of output devices on IDNet peripherals, such as
piezo sounders, the output voltage increases to 35V to provide sufficient voltage at the end of line to
activate the piezo. The higher voltage state is an alarm condition for the purpose of standby battery
calculation. The 30V output is the normal condition, and is used to prolong battery standby. The CPU
will activate the boost feature when 10 LED, Piezo or other outputs are activated.
3. The battery circuit is supervised for overcurrent, low battery and missing or depleted battery.
Continued on next page
Table 2-14. Input and output specifications
AC input specifications
MSS in 120V FACP 4 A maximum
120 VAC @ 60 Hz, nominal (Note 1)
MSS in 220/240V FACP 2 A maximum
220/230/240 VAC @ 50 or 60 Hz (Note 1)
DC output specifications
All MSSs Minimum: 19.9 VDC (special applications)
Maximum: 31.1 VDC
Ripple: 2 VDC p-p @ full load (8 A)
MSS with IDNet output (see
note)
30V or 35V (Note 2)
Battery charger specifications (Note 3)
Input voltage range 21-33 VDC
Output float voltage
27.4 VDC ±500 mV @ 20
o
C, temperature compensated at -
24 mV to -36 mV/×C (32
o
F to 120
o
F or 0
o
C to 49
o
C)
High voltage output 29.1 V @ 3.3 A
Output current limit 1.4 A for 6.2 - 18 Ah battery
3.3 A (default; for 18-50 Ah battery- Canadian; for 18-110 Ah
battery - U.S.)