Specifications

51
SLC 500 Programmable Controllers and I/O Modules
Example Worksheet for Selecting 1746 Power Supplies for the Example System
For a detailed list of device load currents, see page 54. Remember to consider future system expansion when selecting a power supply.
Procedure
1. For each slot of the chassis that contains a module, list the slot number, the catalog number of the module, and its 5V and 24V
maximum currents. Also include the power consumption of any peripheral devices that may be connected to the processor other than a
DTAM, HHT, or PIC—the power consumption of these devices is accounted for in the power consumption of the processor.
Chassis Number 1 Maximum Currents Chassis Number 2 Maximum Currents
Slot Number Catalog Number at 5V dc at 24V dc Slot Number Catalog Number at 5V dc at 24V dc
Slot 0 1747-L511 0.350A 0.105A Slot 0 1747-L514 0.350A 0.105A
Slot 1 1746-IV8 0.050A — Slot 1 1746-OW16 0.170A 0.180A
Slot 2 1746-OB8 0.135A — Slot 2 1746-NO4I 0.055A 0.195A
Slot 3 1746-OA16 0.370A — Slot 3 1746-NO4I 0.055A 0.195A
Slot Slot 4 1746-NO4I 0.055A 0.195A
Slot Slot 5 1746-NO4I 0.055A 0.195A
Slot Slot 6 1746-IO12 0.090A 0.070A
Slot Slot
Peripheral Device A/C — 0.085A Peripheral Device A/C — 0.085A
Peripheral Device Peripheral Device
2. Add the loading currents of all 0.905A 0.190A 2. Add the loading currents of all 0.830A 1.220A
the system devices at 5 and 24V dc the system devices at 5 and 24V dc
to determine the Total Current. to determine the Total Current.
3. For 1746-P4 power supplies, calculate the total power consumption of all system devices. If you are not using a 1746-P4, go to step 4.
Current Multiply by = Watts Current Multiply by = Watts
Total Current 0.905A 5V 4.525W Total Current 0.830A 5V 4.15W
at 5V dc at 5V dc
Total Current 0.190A 24V 4.56W Total Current 1.220A 24V 29.28W
at 24V dc at 24V dc
User Current 0.500A 24V 12.00W User Current 0.500A 24V 12.00W
at 24V dc at 24V dc
Add the Watts values to determine Total Power 21.085W Add the Watts values to determine Total Power 45.43W
(cannot exceed 70 Watts) (cannot exceed 70 Watts)
4. Choose the power supply from the list of catalog numbers shown below. Compare the Total Current required for the chassis with the
Internal Current capacity of the power supplies. Be sure that the Total Current consumption for the chassis is less than the Internal
Current Capacity for the power supply, for both 5V and 24V loads.
Catalog Number Internal Current Capacity Catalog Number Internal Current Capacity
at 5V dc at 24V dc at 5V dc at 24V dc
1746-P1 2.0A 0.46A 1746-P1 2.0A 0.46A
1746-P2 5.0A 0.96A 1746-P2 5.0A 0.96A
1746-P3 3.6A 0.87A 1746-P3 3.6A 0.87A
1746-P4 (see step 3) 10.0A 2.88A 1746-P4 (see step 3) 10.0A 2.88A
1746-P5 5.0A 0.96A 1746-P5 5.0A 0.96A
1746-P6 1746-P6
1746-P7 1746-P7
Required Power Supply 1746-P1 Required Power Supply 1746-P4