Data sheet, Safety considerations (continued), Feature description – GE Industrial Solutions JRW450U Orca Series User Manual
Page 7
GE
Data Sheet
JRCW450U Orca Series; DC-DC Converter Power Modules
36–75 Vdc Input; 48.0Vdc Output; 450W Output
June 7, 2013
©2012 General Electric Company. All rights reserved.
Page 7
Safety Considerations (continued)
All flammable materials used in the manufacturing of these
modules are rated 94V-0, or tested to the UL60950 A.2 for
reduced thickness.
The input to these units is to be provided with a maximum 25
A fast-acting or time-delay fuse in the ungrounded input
connection.
To insure safety compliance, the temperature at T
ref
(Figure
16) at full load should not exceed the listed temperature when
operating at the indicated input voltage.
Test
Condition
75V
dc
input
36V
dc
input
T
ref1
or
T
ref2
T
ref3
T
ref1
or
T
ref2
T
ref3
No
heat
sink 83.4°C 130°C 89.6°C 130°C
1 in. heat sink 73.8°C
130°C 90.2°C
130°C
Cold
wall 75.5°C 130°C 95.0°C 130°C
Feature Description
Remote On/Off
Two remote on/off options are available. Positive logic turns
the module on during a logic high voltage on the ON/OFF pin,
and off during a logic low. Negative logic remote On/Off,
device code suffix “1”, turns the module off during a logic high
and on during a logic low.
To turn the power module on and off, the user must supply a
switch (open collector or equivalent) to control the voltage
(V
on/off
) between the ON/OFF terminal and the V
IN
(-) terminal
(see Figure 10). Logic low is 0V ≤ V
on/off
≤ 0.8V. The maximum
I
on/off
during a logic low is 1mA, the switch should be maintain
a logic low level whilst sinking this current.
During a logic high, the typical maximum V
on/off
generated by
the module is 5V, and the maximum allowable leakage
current at V
on/off
= 5V is 50μA.
If not using the remote on/off feature:
For positive logic, leave the ON/OFF pin open.
For negative logic, short the ON/OFF pin to V
IN
(-).
Figure 10. Circuit configuration for using Remote On/Off
Implementation.
Overcurrent Protection
To provide protection in a fault output overload condition, the
module is equipped with internal current limiting protection
circuitry, and can endure continuous overcurrent by providing
constant current output, for up to 4 seconds, as long as the
output voltage is greater than V
trimMIN
. If the load resistance is
too low to support V
trimMIN
in an overcurrent condition or a
short circuit load condition exists, the module will shut down
immediately.
A latching shutdown option is standard. Following shutdown,
the module will remain off until the module is reset by either
cycling the input power or by toggling the on/off pin for one
second.
An auto-restart option (4) is also available in a case where an
auto recovery is required. If overcurrent greater than 12A
persists for few milli-seconds, the module will shut down and
auto restart until the fault condition is corrected. If the output
overload condition still exists when the module restarts, it will
shut down again. This operation will continue indefinitely, until
the overcurrent condition is corrected.
Over Voltage Protection
The output overvoltage protection consists of circuitry that
monitors the voltage on the output terminals. If the voltage on
the output terminals exceeds the over voltage protection
threshold, then the module will shut down and latch off. The
overvoltage latch is reset by either cycling the input power for
one second or by toggling the on/off signal for one second.
The protection mechanism is such that the unit can continue
in this condition until the fault is cleared.
An auto-restart option (4) is also available in a case where an
auto recovery is required.
Remote sense
Remote sense minimizes the effects of distribution losses by
regulating the voltage at the remote-sense connections (see
Figure 11). For No Trim or Trim down application, the voltage
between the remote-sense pins and the output terminals
must not exceed the output voltage sense range given in the
Feature Specifications table i.e.:
[V
o
(+)–V
o
(-)] – [SENSE(+) – SENSE(-)] 2% of V
o,nom
The voltage between the Vo(+) and Vo(-) terminals must not
exceed the minimum output overvoltage shut-down value
indicated in the Feature Specifications table. This limit
includes any increase in voltage due to remote-sense
compensation and output voltage set-point adjustment (trim).
See Figure 11. If not using the remote-sense feature to
regulate the output at the point of load, then connect
SENSE(+) to V
o
(+) and SENSE(-) to V
o
(-) at the module.
Although the output voltage can be increased by both the
remote sense and by the trim, the maximum increase for the
output voltage is not the sum of both. The maximum increase
is the larger of either the remote sense or the trim. The
amount of power