© Ernst Nagel GmbH 2S Trimmer Service Manual en.doc Rev.1.0. 20.07.2011
125
Contents
7. PCB’S
(continued)
7.2 LED’S & TEST POINTS
(continued)
7.2.4 Interlock PCB3
This board interrupts power to the motor control boards if:
- K2 is open because one of the Interlock switches is open
(S3, S4, S7 or S8)
- PCB6 has not released because:
- 36V is outside Range
- 24V is outside Range
- Top Cover is open (S19 closed)
- Trim Waste Bin is open (S9 closed)
- K2 is not activated (contact closed)
D6: Red LED is ON when unregulated 36V is present. If
machine is interlocked (i.e. the Top Cover or Trim
Waste Bin is open and 36V is cut off) or 36V is
missing, LED is OFF.
The
unregulated
36V
can
be
measured
between
+UNREG
Test
Point
and
PGND
Test
Point.
D7: Red LED is ON when 24V is present. If machine is interlocked (i.e. the Top Cover or Trim Waste Bin is
open) LED will still be ON.
It will also be ON if 36V is present but not 24V. In such a case the 24V stabilizing circuit on the Interlock
PCB would be defective. To establish that actual 24V is present, measure b24V Test Point and
PGND Test Point.
D9: At power up, if all covers are closed, input power is checked to be within allowed range. If input voltage
is too high or too low a fault is presented to the operator and machine will be inoperable. If the input
voltage is within allowed range, and all covers are closed, the interlock relay is activated.
When interlock relay is activated the LED D9 is ON. Relay will only close if Interlock switches are also
closed. If an interlock relay fault is detected, that is presented to the operator and machine will be
inoperable.
During normal operation the LED D9 is ON when covers are closed. If a cover is open LED D9 is OFF.
Note that the fault codes are only visible in operator mode.
TP1
:
Incoming unregulated 36V, before interlock relay. Measure between Test Point TP1 and Test
Point PGND using a voltmeter. The voltage will be shown on the voltmeter regardless of the
voltage being outside allowed range 29-43V.
+
UNREG
:
Outgoing unregulated 36V, after interlock relay. Measure between Test Point +UNREG and
Test Point PGND using a voltmeter. The voltage will be shown on the voltmeter unless:
- Voltage is outside allowed range 23-43V. Voltage will be 0V.
- Machine is interlocked (i.e. the top cover is open). Voltage will be 0V.
+
24V
: Stabilised 24V made from incoming unregulated 36V, before interlock relay.
Measure between Test Point +24V and Test Point PGND using a voltmeter. The voltage will
be shown on the voltmeter. Range 23-25V.
PGND (TP2)
: Power Ground is the minus when measuring either unregulated 36V (+UNREG) or 24V (+24V).
Contents
8. NVM Values
TP1
D6
D7
D9
Fig. 7.9
+UNGREG
+24V
PGND (TP2)
