User's Manual

DRAFT 1
84 Installation TB9300 Installation and Operation Manual
© Tait Limited May 2013
5.6.3 Connecting DC Power
The PMU is designed to accept a nominal 12VDC, 24VDC or 48VDC
input (depending on the model) with negative or positive ground. There is
a minimum DC startup threshold to prevent damaging a battery which has
little capacity left.
You must connect the DC supply from the battery to the PMU via a fuse or
DC-rated circuit breaker with a contact separation of 3mm, and with the
appropriate rating, as shown in the table below. The DC input leads should
be of a suitable gauge to ensure less than 0.2V drop at maximum load over
the required length of lead.
Terminate and insulate the DC input leads to protect them from
accidentally shorting to the subrack if the PMU is removed before the leads
are disconnected. Protective covers for the DC terminals are supplied with
each PMU.
We recommend a screw torque of 18–20lbf·in (2–2.25N·m).
Nominal Supply
Voltage
Input Voltage
Range
Circuit Breaker/
Fuse Rating
a
a. The actual current consumption of the base station will be lower than these re-
quirements (refer to the Specifications Manual for more information).
Recommended
Wire Gauge
b
b. For a length of 5ft to 6.5ft (1.5m to 2m) (typical).
12VDC 10VDC to 16.8VDC 60A 2AWG / 35mm
2
24VDC 20VDC to 33.6VDC 30A 5AWG / 16mm
2
48VDC 40VDC to 60VDC 15A 8AWG / 8mm
2
Figure 5.9 Recommended DC power connection
Battery
Circuit Breaker
or Fuse
PMU