Installation
18
GA 12.137/2.02 - 05/2002
Connecting the Sub-D connectors (option)*
Refer to Section 3.5 for the RS 232 interface.
Warning
For protection against thermal cut-outs, if
this compressor unit as part of a refrigerati-
on system is used in a medical electrical
system (e.g. a MRI system), the compres-
sor unit’s operation must be monitored by
the higher level control of the medical
system, e.g. via the compressor’s built-in
remote and/or RS 232 interface.
If required, connect the REMOTE connector.
Maximum contact load 30 mA total on signal lines.
Do not apply 24 V DC permanently to pin 3 (Reset).
(Recommendation for reset: pulse > 100 ms)
Caution
Do not connect to “free“ pins as they are
already internally connected.
The compressor unit satisfies EU Directives regulating
electromagnetic compatibility (EMC). To ensure that
compatibility is maintained, adhere to the following
installation instructions:
•
Use the prescribed Leybold connector lines to
connect the cold head.
•
Use shielded cables to connect the Sub-D connec-
tors and attach the shielding to the metal housings of
the Sub-D plugs.
Operation via the interfaces
The interfaces can be used to run the compressor unit in
parallel to the control buttons for ON, OFF and SELECT.
The control lines for the REMOTE interface respond to
the rising or falling flank of a +24 V DC signal.
Example:
0 V
⇒
+24 V at pins 4 and 6: Compressor ON
+24 V
⇒
0 V at pins 4 and 6: Compressor OFF
Before changing the operating mode, it is necessary to
first switch off the compressor unit and the cold head
while in the "old” operating mode and then to switch on
again in the "new” operating mode.
Failure to observe this rule may result in undefined ope-
rating states, for example:
The compressor unit is running in the REMOTE mode;
24 V is present at pins 4 and 6. The compressor unit is
(contrary to the rule) switched off with the OFF button.
Then it is off although the 24 V signal is present at pins
4 and 6.
* The required counter plug is available e.g. from
Framatome Connectors International:
REMOTE:
25-pole, solder version, male
DB25P064TX
Metallized housing, straight exit
8655 2181
