12
SLC 500™ Power Supplies
Power Supply Undervoltage Operation
SLC 500 controllers continue to operate (hold-up) for a short period of time if the
input voltage to the power supply drops below the recommended operating
voltage range. The controller continues to scan the user program and control I/O
during this time. CPU hold-up for each power supply is shown on pages 12 and 14.
SLC 500 controllers turn OFF (stop scanning and disable outputs) if input voltage to
the power supply is removed or drops below the recommended operating range
for a period exceeding the CPU hold-up time. The controller resumes operation
automatically when the input voltage is restored to normal.
If the input voltage to the 1746-P7 power supply falls into a range of 4 to 9V for a
period exceeding the CPU hold-up time, the controller turns OFF and will not turn
back ON until:
• input voltage is increased to 11V dc.
General Specifications (Power Supplies 1746-P1, -P2, -P3,
and -P4)
Description:
Line Voltage
Typical Line Power
Requirement
Maximum Inrush
Current
Internal Current
Capacity
(2)
Fuse Protection
24V dc User Power
Current Capacity
24V dc User Power
Volt. Range
Max. User-supplied
overcurrent
(7)
protection
Ambient Operating
Temperature
(8)
Isolation
(10)
CPU Hold-up Time
Publication 1746-IN004D-MU-P - May 2003
Specification: 1746-
P1
P2
85-132/170-265V ac
47-63 Hz
135 VA
180 VA
20A
2A at 5V dc
5A at 5V dc
0.46A at 24V dc
0.96A at 24V dc
1746-F1 or
1746-F2 or
(3) (4)
equivalent
equivalent
200 mA
18-30V dc
15A
0°C to +60°C (+32°F to +140°F)
Current capacity is derated 5% above +55°C.
1800V ac RMS for 1 s
20 ms (full load) 3000 ms (no load)
P3
19.2-28.8V dc
90 VA
3.6A at 5V dc
0.87A at 24V dc
1746-F3 or
(3) (5)
(3) (6)
equivalent
Not Applicable
Not Applicable
(9)
None
5 ms (full load)
1000 ms (no load)
P4
85-132/170-250V ac
47-63 Hz
150 VA
45A
10.0A at 5V dc
(1)
2.88A at 24V dc
Fuse is soldered in
place.
(1)
1A
20.4-27.6V dc
15A
0°C to +60°C
(+32°F to +140°F)
no derating
2600V dc for 1 s
20 ms (full load)
3000 ms (no load)