Technical_reference - 第87页

Technical Service Manual 87 Revision Dat e: August 2004 ELECTRICAL GROUNDING OF OVEN GENERAL: 1) All ground wires have gr een or green/yellow insulation. Ground wires without green or green/yellow insulation are identifi…

Technical Service Manual 86 Revision Date: August 2004

COMPUTER SYSTEM

The computer system must be set up and connected to the Vitronics-Soltec Oven. The monitor and keyboard are placed

on the swing arm / light tower. The keyboard, monitor, and computer connect together. The connections on the back of

the computer are color coded, and they are different sizes/shapes to help connect them properly. (If the keyboard/mouse

does not function, swap the two connectors on the back of the Computer.)

One data cable must be connected from the computer to the oven.

Two 120VAC power cables (they are identical) are factory-wired for the Computer and Monitor. Plug the power cables

into the receptacles on the rear of the Computer and Monitor.

CONTROL CIRCUIT

Test procedure for safety interlock circuit

Þ Activate all circuit breakers.

Þ Ensure all E-stop switches are pulled out.

Þ Log into the Oven control Program and reset the E-Stop Alarm

Þ The E-stop relays K37 & K38 should be energized. If not, check the output of the control transformer using a

Voltmeter at wires #3 and #2. If voltage is present, but K37 & K38 are not energized, there is a break in the series

connection of safety interlocks.

Þ Check that each E-stop and safety interlock switch de-energizes K37 & K38.

Note: The enclosure safety interlock switches mentioned above are optional and do not exist on all ovens.

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.