Thermal Dynamics MERLIN 6000, Руководство по обслуживанию, Страница: 44 / 112

SERVICE TROUBLESHOOTING 38 Manual 0-2569
• Before cutting (preview) and with the three deci-
mals ON, the display indicates the CSD poten-
tiometer setting instead of the main current
control.
The Remote Control display full scale is 150A if one
Power Supplyis used or 300A if two (Master and
Slave) are used.
The following describes the flow of the SLAVE IS ON
signal through the system:
• When the Slave Power Supply is present and
turned ON, the SLAVE IS ON signal is present.
• Signal is active low (less than 2 vdc) from the
Slave Power Supply Logic PCB J1-20 to J15-17.
• The signal then goes through the Parallel cable
to the Master Power Supply Isolation PCB.
Refer to Section 4.05-T Isolation and Parallel
cable.
• The Master Power Supply Logic PCB receives
the low SLAVE IS ON signal at J4-4.
• Master Power Supply Logic PCB then sends
out an active high (5 vdc) on J1-20 (Remote
Control uses 5 vdc logic).
• The active high 5 vdc signal is then sent to the
Master Power Supply connector J15-17 and out
the remote interface cable. If there is no Slave
Power Supply or it is not turned ON, J15-17
should be low.
• Signal then goes to the Remote Control connec-
tor J37-14 which sets the Remote Control
dispaly to 300A full scale. If there is no Slave
Power Supply or it is not turned ON the Re-
mote Control display is set to 150A full scale.
The Current Control potentiometer voltage of 3.3 to
10 vdc gives a display of 50 to 150A or 100 to 300A, if
the Slave supply is ON. The voltage comes from the
Master Power Supply Switching Control PCB at J7-2.
It then is routed out through the Master Power Sup-
ply connector J15-3. The voltage then goes through
the remote interface cable and on to the Remote Con-
trol connector J37-1. This causes the current to be dis-
played from 50 to 150A or 100 to 300A, if the Slave
supply is ON. In the preview mode (not cutting) the
display signal at J7-2 should equal the control poten-
tiometer wiper voltage at J7-18 checked in step 3
above.
• If voltage is incorrect, then the Switching Con-
trol PCB is faulty.
When cutting, each Power Supply (Master and Slave)
monitors the actual output amps with their own Shunt
Amp PCB. Each Power Supply Shunt Amp PCB out-
put is 5.45 vdc for 150A and is sent to the Switching
Control PCB at J9-5 in each Power Supply. Each
Switching Control PCB converts the voltage to 10 vdc
for 150A.
The resulting signal is set through the system as fol-
lows:
• In the Slave Power Supply the voltage is sent
out the Switching Control PCB at J7-2 as OUT-
PUT SIGNAL TO MASTER.
• This signal is then sent to the J15-3 connector
and out through the Parallel Cable to the Mas-
ter Power Supply connector J15-3. Refer to
Section 4.05-T, Isolation PCB and Parallel
Cable.
• Master Power Supply Switching Control PCB
receives the OUTPUT SIGNAL TO MASTER
signal at J7-11.
Signal is then averaged with the Master Power Sup-
ply output signal.
• The average signal is then sent out to remote
display on J7-2 as DISPLAY SIGNAL TO RE-
MOTE.
• This signal is then sent out the Master Power
Supply connector J15-3 to the Remote Control.
The following is an example of how the averaging cir-
cuit functions:
Master Power Supply outputs 10 vdc (150A) and
the Slave Power Supply outputs 6.67 vdc (100A).
The average is (10 + 6.67)/2=8.33 vdc. With the
display set for 300A full scale, 10 vdc equals 300A,
then 8.33 vdc will equal approximately 250A.
Normally, both the Master and Slave Power Sup-
plies should have the same output, except if there
is a fault both supplies.
5. Corner Slowdown (CSD)
Corner Slowdown (CSD), a CNC signal, is also re-
ferred to as standoff inhibit or corner current reduc-
tion. The CNC signal comes from the cutting machine
controller to inhibit the standoff control when cutting
speed reduction is desired. Speed reduction may be
needed for cutting around corners where high speeds
would adversely affect the standoff regulation. It also
can be used to reduce cutting current when the cut
speed is lowered.
A contact closure between J29-7 and 8 or J6-7 and 8 of
the Remote Control (RC 6010) sends an active low sig-
nal to the Standoff Control (SC10) via J5-21 which
turns OFF the Standoff Control THC ACTIVE indica-