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TPCMQ48 SERIES
INSTALLATION & OPERATING MANUAL
Manual No. tpcmq48-4
tpcmq48-man-rev4-0116.indd
12.6
Overvoltage Protection
- The power supply has two internal O.V.P. protection circuits. One
operates at a fixed voltage level and the other is programmable by the PMBus. The fixed
O.V.P. levels are defined below:
Model
Fixed OVP Point
(nominal)
TPCMQ48-12/54
21.1V
TPCMQ48-24/29
31.9V
TPCMQ48-27/26
TPCMQ48-48/21
59.4V
TPCMQ48-54/18
The O.V.P. circuit has a latching function and will not allow the unit to automatically restart.
In order to reset the O.V.P. latch, the DC input must be cycled off for at least 5 seconds
before turning back on.
12.7
Overcurrent and short circuit protection
- The power supply will provide a constant
current limit in the event of an overload on the output. If the output voltage of the power
supply falls below a certain level, the power supply will enter a ‘hiccup’ mode of operation.
Removing the overload or short circuit will allow normal operation to resume. The voltage
at which the ‘hiccup’ mode of operation occurs is programmable down to the minimum
default setting.
12.8
Remote Sensing
- Remote sensing connections are made to the +Sense and-Sense pins on
the connector. Remote sensing is not available on the +5V Standby output. Remote sensing
is used to regulate the output voltage at the point of load by compensating for the voltage
drop in the wires to the load. The +Sense lead must be connected to the +Ve side of the load
and the -Sense lead to the -Ve side of the load. The sense leads should be a color-coded,
twisted pair of AWG no. 22 or 24 copper wire.
Remote sensing can compensate for a total voltage drop of 0.5V, or 0.25V per load wire. The
sense leads should not exceed 10 feet (3 meters) in length. If remote sensing is not required,
the sense leads may be left open for local sensing at the output terminals.
Be careful not
to reverse the sense lead connections, as this could damage the unit.
12.9
Alarm, Control & Supervisory Signals
- All alarm, control and supervisory signals are
available on the connector at the rear of the unit. See section 9.2 for a complete description.
All logic signals are TTL level compatible and are referenced to -Sense.
12.10 I²C Option
– The I²C serial bus is available on the connector at the rear of the unit.
