Technical_reference - 第88页
Technical Service Manual 88 Revision Dat e: August 2004 E - A SSOCIATED SUBSYSTEM S TRUE N2 / AIR SW ITCHING TRUE N2 / AIR Switching is: ! Standard on all NITROGEN ovens ) An option (NO T ins talled on all ovens) On Nitr…
Technical Service Manual 87 Revision Date: August 2004
ELECTRICAL GROUNDING OF OVEN
GENERAL:
1) All ground wires have green or green/yellow insulation. Ground wires without green or green/yellow insulation
are identified using green or green/yellow tape.
2) The main electrical panel has a single ground terminal. All grounds must be connected to the ground
terminal.
3) Bare copper grounding wire inserted into an aluminum grounding block should be coated with an oxidation
inhibitor. Copper to aluminum has a natural galvanic reaction, which will degrade the electrical connection in
a short time. Inhibitor is not required when ferrules are used.
4) Use long nose pliers when inserting a ground wire into a double layered ground block. Insert the wire
completely into the block for a proper ground bond.
5) Ground blocks should be mounted on a clean and paint free surface. Use a star washer under the mounting
screws.
Test procedure for system ground continuity
1) Check continuity between the main ground terminal of the oven and the ground terminal on the mains
connecting plug or distribution board using an Ohmmeter.
2) Check continuity from the mains ground terminal of the oven to each individual component using an
Ohmmeter.
3) The resistance values should not exceed one Ohm.
Test procedure for insulation leakage (MEGGER [or Resistance] TEST)
1) Disconnect the system from the mains supply
2) Connect the three phases together at the mains supply connection point on the oven.
3) Disconnect the Circuit Breakers supplying the control circuit transformer and the circuit breaker supplying
the inverter.
4) Disconnect the computer and all peripheral equipment from the oven.
5) Connect an insulation test meter between one of the three phases and the ground connection point.
6) Turn on the Main Disconnect and test the system insulation for leakage at twice the single-phase voltage.
For example, for 240 VAC phase to neutral, check insulation at 500 Volts.
7) The resistance should be at least 1 MegOhm.
Technical Service Manual 88 Revision Date: August 2004
E - ASSOCIATED SUBSYSTEMS
TRUE N2 / AIR SWITCHING
TRUE N2 / AIR Switching is:
!
Standard on all NITROGEN ovens ) An option (NOT installed on all ovens)
On Nitrogen (N2) Reflow Ovens, the N2 / Air Automatic Switching Option permits switching from a Nitrogen to an Ambient
Air (room air, not compressed air) atmosphere.
DESCRIPTION
This configuration is for customers who want a nitrogen oven, but intend to run both air and nitrogen atmospheres. The
machine is set up to optimize nitrogen performance, minimize 02 levels, minimize N2 consumption, and minimize tunnel
maintenance.
APPLICATION
The True N2 / Air switching provides automated switching from the N2 Mode to Air Mode with all of the benefits of a true
air machine. Any application considering air operation to any extent should incorporate this option.
BENEFITS
In addition to the benefits of Nitrogen, this option offers the ability to run a true air process, with the benefits long
associated with air machines (economical gas flow, and continuously flushing cleanliness). Both modes are controlled
automatically by the selection in the recipe file.
FUNCTION
A series of valves are added to the individual cell intakes, the Controlled Exhaust, and the FFC manifold to allow
automatic control of gas flows in the machine.
N2 MODE-
Nitrogen flow to the machine automatically closes individual cell intake valves, closes the Air Controlled Exhaust
valve, and opens the Flux Flow Control manifold valve. In this configuration the machine functions as the
standard N2 FFC machine.
AIR MODE-
Upon closing the N2 solenoid, individual cell intake valves automatically open, the Controlled Exhaust valve
opens, and the FFC manifold valve closes (stopping gas recirculation). A valve on the far end of the FFC
manifold opens to allow air intake into the manifold. In this configuration the machine functions as an Air machine
MAINTENANCE:
The True N2 / Air switching system requires minimal maintenance if operating properly, using recommended flows
settings, and periodic checks, as outlined in the operator manual. Periodic (every six months) inspection of the valve
cylinders and valve seats is recommended to insure proper operation. Nitrogen lines to the valves should be checked for
leaks.
Technical Service Manual 89 Revision Date: August 2004
BATTERY BACK-UP FOR PC, CONTROLLER, CONVEYOR, AND HOOD LIFTS
The UPS Battery Back-up is:
! Standard, (installed on all ovens) ) An option, (NOT installed on all ovens)
DESCRIPTION:
In case of a power failure, the UPS, (uninterruptable power supply) battery provides power to the PC, oven controller,
conveyor, and hood lift system. This provides a sufficient amount of time to completely empty out the Reflow Oven of any
product that may have been in process when the power failure occurred. The oven controller will provide an audible
alarm, and the PC will provide a message indicating the operation of the UPS system. The Battery Back-up Option will
also allow the Reflow Oven operator to open the Hoodlift should there be a need to remove product from the oven due to
the power failure.
NOTE: The length of time the UPS will operate is dependent on oven size, not time. The UPS will operate for a period of
time equal to the amount of time it will take a PCB to travel the full length of the oven at the speed contained in the
running recipe at the time of the power failure. After this period, the UPS will turn off, shutting down the PC, oven
controller, conveyor, and hoodlift system.
(If the operator wishes to prevent the conveyor from running, the UPS backup battery should be disabled through the
Oven Control Program before a power failure.)
“POWER ON” DEFAULT FOR THE UPS BACKUP BATTERY:
Each time the oven’s PC is turned on or resets the UPS backup battery unit is reset to the previous status (on or off).
The oven software remembers the last configuration, even after being ‘reset'.
PLEASE READ THE UPS MANUFACTURERS MANUAL DELIVERED WITH THE OVEN
PRODUCT TRACKING AND ALARM
Product Tracking and Alarm is:
! Standard, (installed on all ovens) ) An option, (NOT installed on all ovens)
The product tracking option has two photo-sensors. One mounted at the Onload end and one at the Offload end
of the oven. Boards loading onto the conveyor are detected by the sensor and counted. The program calculates board
travel through the oven, and each board is expected to pass under the Offload sensor within a time period based on the
conveyor speed (as measured in PPI) and the oven length.
If a board does not pass under the Offload sensor within the calculated time, the "Board Dropped Alarm" is activated.
The product length specified in the Product Definition determines the board length displayed on the screen.
Additional information about Product Tracking is available in the XPM2 User Manual.