USER GUIDE | UG:115
PFC Mini
TM
Power Factor Corrected AC-DC Switcher
March 2010
Contents
Overview
of Product
Mechanical
Considerations
PFC Mini
Do’s and Don’ts
Technical Description
PFC Mini
Configuration
Layout
Part Numbering
Quick Install
Instructions
Mechanical Drawings
Output Connectors
Interface Connections
Output Power
De-rating
Specifications
Current Share Boards
Low Leakage Version
Low Output Ripple
Page
1
2
3
3
5
Overview
6
7
The PFC Mini is an extremely low profile, 1 RU, switching power supply that combines
the advantages of power factor correction and high power density. This design guide
covers both standard and rugged chassis COTS (MI) versions of the product. The PFC
Mini can provide up to six isolated outputs (three slots) and each slot accommodates
the following Vicor DC-DC Converters.
VI/E-200 and VI/E-J00 series:
One VI/E-200 or Two VI/E-J00 converters
Maxi, Mini Micro series:
One Maxi, Two Mini converters (Micros cannot be used)
The use of these converters give the PFC Mini the inherent power flexibility typical
of all Vicor products. Using the VSPOC configurator tool available on
vicorpower.
com,
anybody can now configure a PFC Mini (and other Vicor power supplies) online.
Accepting input voltages of 85 Vac to 264 Vac, and 100 Vdc to 380 Vdc, the PFC Mini can
provide up to 1,500 Watts in a package size of 1.72" H (43,6 mm) x 6" W (152,4 mm)
x 12.2" L (309,9 mm). The PFC Mini is factory configured to meet user requirements.
Note:
If you have a PFC Mini that shipped from October 2005 onwards, please see Page 19
for more details.
10
11
12
20
21
24
27
27
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Page 1
Standard Features
n
Power Factor Correction: 0.99 at 115 Vac; 0.95 at 230 Vac
n
Universal Input: 85 – 264 Vac, 47 – 500 Hz, or 100 – 380 Vdc
n
Power Output: 1,500 W at 230 Vac; 800 W at 115 Vac
n
Up to 6 isolated outputs (3 slots)
n
Fan cooled
n
Full power to 45°C; half power at 65°C
n
Conducted EMI:
VI-200/VI-J00 series:
FCC Class B
EN55022 Class B
Maxi, Mini, Micro series:
FCC Class A
EN55022 Class A
(certain configurations meet EN55022 Class B)
n
Harmonic Distortion complies with EN61000-3-2
n
AC Power OK status signal
n
Autosense (for more information, see Page 8 and Page 14)
n
Output overcurrent protection on all outputs
n
Output overvoltage protection (not applicable when using VI-J00)
n
Output overtemperature limiting (not applicable when using VI-J00)
n
Ride-through (hold-up) time: >20 ms at 1,200 W load (nominal line)
n
Size: 1.72" H (43,6 mm) x 6" W (152,4 mm) x 12.2" L (309,9 mm)
n
Safety Agency Approvals: CE Mark, cTÜVus, UL
(
Note:
Certain MI chassis may not carry all safety certs
)
Optional Features
n
Extended temperature range output converters
n
Current share board - see Page 24
n
RAM modules for low noise applications - see Page 27
n
Connector kit available (#19-130047)
n
Low leakage available - see Page 27
n
Office environment fan - see Page 27
n
MI chassis specific options
-
-
-
-
Mil-STD 810 for Shock and Vibration
Mil-STD 704 and 1399 for overvoltage and transients
-40°C Operation
Conformal coating - contact factory
Mechanical Considerations
The PFC Mini can be mounted on either of two surfaces using standard 8-32 (4 mm) size
screws. Maximum allowable torque is 4.4 in. lbs., and the maximum penetration is
0.16 in. (4 mm).
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When selecting a mounting location and orientation, the unit should be positioned so
airflow is not restricted. Maintain a 2" (5,1 cm) minimum clearance at both ends of the
PFC Mini, and route all cables so airflow is not obstructed. The power supply draws air
in at the fan side/AC input side and exhausts air out the load side. If airflow ducting is
used, avoid sharp turns that could create back pressure. The fans move approximately
20 CFM of air.
Avoid excessive bending of output power cables after they are connected to the output
terminals. For high-current outputs, use cable ties to support heavy cables and minimize
mechanical stress on connectors. Be careful not to short-out to neighboring outputs. The
maximum torque recommended on output nuts is 10 in. lbs.
Avoid applications in which the unit is exposed to excessive shock or vibration levels. In
such applications, a shock-absorbing mount design is required.
PFC Mini Do’s and Don’ts
n
If Sense jumpers are removed, do not leave Sense lines open
(especially if unit does not have Autosense). Sense lines must be terminated to
their respective outputs. Use twisted pair 20-22 AWG wire when installing
Remote Sense.
n
NEVER
disconnect the +Out and -Out load wires while the supply is operating as
disconnecting WILL cause damage to the power supply. Ensure load wires connected
before remote sense connected.
n
To prevent damage to supply, verify polarity of remote sense connection before
turning supply on.
n
Always turn the power supply off before disconnecting input or output wires.
n
Do not restrict airflow to the unit. The cooling fan draws air into the unit and forces it
out at the output terminals.
n
Run the output (+/–) power cables next to each other to minimize inductance.
n
Do not repair or modify the power supply in any manner. Doing so will void the
warranty. Contact Factory.
n
Insert proper fault protection at power supply input terminals (i.e., a fuse).
n
Use proper size wires to avoid overheating and excessive voltage drop.
n
Output voltages over 60 Vdc, whether from individual modules or series arrays, are
considered as hazardous secondary outputs under UL60950. Appropriate care must
be taken in design implementation of the supply.
Technical Description
The PFC Mini consists of an offline single phase, power-factor-corrected front end, EMI
filter, cooling fan, customer interface, associated housekeeping circuits, and a selection
of Vicor’s DC-DC converters.
Input AC mains voltage is applied to a terminal block. The input current is passed
through an EMI filter designed to meet conducted noise limit “B” specifications in
FCC Part 15 and EN55022, Class B (with VI-200/VI-J00 series modules. If Maxi, Mini,
Micro series modules are used, it meets FCC Class A and EN55022 Class A. (Certain
configurations meet Class B).
At start-up, inrush current is limited by a PTC thermistor. The PTC is shunted out shortly
after initial power-up by a DC bus voltage sense circuit driving a relay. After rectification,
the input voltage is put through a boost converter that keeps the AC input current
sinusoidal and synchronized with the input AC voltage (in compliance with
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Page 3
EN61000-3-2). The boost converter delivers a regulated input to the hold-up capacitors
and a high-voltage backplane. The backplane supplies power to the DC-DC converters
that provide the desired low voltage regulated outputs.
Voltage conversion is achieved by Vicor’s family of zero-current switching (ZCS) DC-DC
converters. These are forward converters in which the main switching element switches
at zero current. This patented topology has a number of unique attributes: low switching
losses; high frequency operation, resulting in reduced size for magnetics and capacitors;
excellent line and load regulation; wide adjustment range for output; low EMI/RFI
emission and high efficiencies.
At initial power-up, the PFC Mini outputs are disabled to limit the inrush current and
to allow the DC bus potential to settle out to the correct operating level. A low-power
flyback converter operating with PWM current-mode control converts the high voltage
DC bus into regulated low voltage to power the internal housekeeping circuits and
DC cooling fans.
The internal housekeeping V
CC
comes up within two seconds after the application of
input power. Once the high voltage bus is within operating limits, the AC Power OK
signal asserts to a TTL "1," indicating the input power is OK, and enables the power
outputs. An auxiliary V
CC
output of 5 Vdc sourcing up to 0.3 A is provided for
peripheral use.
An output Enable/Disable function is provided by using an optocoupler to control
Vicor’s DC-DC converters. If the Enable/Disable control pin is pulled low, the
optocoupler turns on and disables the output. The nominal delay associated for an
output to come up when measured from release of the Enable/Disable pin is 5-10 ms.
The General Shutdown function controls all outputs simultaneously and works in a
similar manner.
Figure 1.
Input
Line Filter
Rectifier
Waveform
Sample
Current
Sample
PFC Control
Output Card #3
Customer
Interface
Enable/Disable Control
Power
Output
Soft Start
Circuit
Boost Converter
High Voltage
Bus
Output Card #1
Power
Output
Output Card #2
Power
Output
E/D Control
Fan
Isolated
Housekeeping
Power
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PFC Mini Configuration Layout
AC input
Fan
Fan
AC input
Fan
Fan
S 3 -M 2
S1-M1
S2-M1
S3-M1
S1-M1
S2-M1
S 3-M1
Slot 1
Slot 2
Slot 3
Slot 1
Slot 2
Slot 3
Shown above, are two sample PFC Mini configuration layouts. Due to the configurability
nature of the PFC Mini, various output combinations are possible. See Page 12 for more
information about your output connections. The PFC Mini has three slots and each slot
accommodates either full or half-brick modules.
Please note that the maximum output power of the PFC Mini is 1,500 W at 230 Vac,
800 W at 115 Vac, irrespective of the maximum output power of the modules e.g. if
a PFC Mini is configured with three Maxi modules, on the configuration sheet, the
maximum output power of the module (600 W) is listed. However, irrespective of the
maximum output power of the three Maxi modules (1,800 W), the maximum output
power of the PFC Mini is still 1,500 W at 230 Vac and 800 W at 115 Vac.
When populated with 12 V modules, the maximum output power per slot is
500 W (with other modules it is 600 W). Hence, when a 12 V Maxi module is used,
the maximum output power is limited to 500 W. If a 12 V Mini module is used, the
maximum output power is limited to 250 W.
UG:115
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Applications Engineering: 800 927.9474
Page 5