This topic considers the provision of DC power supplies for a HiperMAX installation.
The equipment can be powered using a regular telecommunication power supply of -48VDC with a VDC return. The specified voltage range is from -40.5 VDC to -57.0 VDC.
The following supplies are required:
Two feeds of -48VDC with a VDC return for each ATCA shelf
Two feed of -48VDC with a VDC return for the GPS Shelf
One feed of -48VDC with return for each outdoor SCRT
Each shelf requires two feeds (one to each PEM module) of -48VDC with a VDC return. Each wire 16mm2 (AWG5).
It is advised that installation power supplies should be provisioned for upgrade to maximum slot occupancy.
14 slot Chassis: Although there are fuses in the power entry circuit of the shelf, the power lines have to be protected on rack level. Shroff recommend 80A breakers based on consumption of 200 watts per slot.
Precise power consumption can be calculated from the following table. Due to a staged start-up, inrush current effects may be ignored.
|
14 Slot Shelf |
Consumption (watts) |
Full Occupancy |
Total Consumption (watts) |
|
Shelf |
50 |
1 |
50 |
|
Shelf Manager |
10 |
2 |
20 |
|
Fan Modules |
44 |
3 |
132 |
|
SDR |
55 |
12 |
660 |
|
Switch |
100 |
2 |
200 |
|
Total power required (watts) |
1062 | ||
5 slot Chassis: Although there are fuses in the power entry circuit of the Shelf, the power lines have to be protected on rack level. Shroff recommend 30A breakers based on consumption of 200 watts per slot.
|
5 Slot Shelf |
Consumption (watts) |
Full Occupancy |
Total Consumption (watts) |
|
Shelf |
40 |
1 |
40 |
|
Shelf Manager |
10 |
1 |
10 |
|
Fan Modules |
44 |
2 |
88 |
|
SDR |
55 |
3 |
165 |
|
Total power required (watts) |
303 | ||
The GPS requires two supplies of -48VDC with a VDC return. Each wire 1.5mm2 (AWG 15).
Power required = 13 Watts (-40C).
Each SCRT requires a single supply of -48VDC with a VDC return. Cable losses should be taken into account.
Power required per SCRT = 56 Watts (-40C).
Each SCRT is suppled using a proprietary cable available in 3, 10, 30 and 100 Metre lengths.