©
National Instruments Corporation
11
NI 1357/1358/1359 Kit Installation Guide
Derating Modules that Share the HVAB
Caution
As a safety precaution, modules that share a common HVAB
must
be derated to
their lowest common voltage rating, even if they do not connect signals to the backplane.
The following examples demonstrate how to derate switch modules:
Example 1
NI SCXI-1000 chassis
NI SCXI-1359 2-slot backplane adapter behind Slots 3 and 4
NI SCXI-1127 (300 V, CAT II) in Slot 4
NI SCXI-1129 (150 V, CAT I) in Slot 3
Both modules share the HVAB. Therefore, the NI SCXI-1127 must not
exceed the rating of the NI SCXI-1129 (150 V, CAT I).
Example 2
NI SCXI-1000 chassis
NI SCXI-1359 2-slot backplane adapter behind Slots 3 and 4
NI SCXI-1127 (300 V, CAT II) in Slot 4
NI SCXI-1129 (150 V, CAT I) in Slot 2
The NI SCXI-1127 does not share the HVAB with the NI SCXI-1129.
Therefore, the NI SCXI-1127 can operate at the full rating (300 V, CAT II).
Example 3
NI SCXI-1000 chassis
NI SCXI-1359 2-slot backplane adapter behind Slots 3 and 4
NI SCXI-1127 (300 V, CAT II) in Slot 4
NI SCXI-1190 (30 V, CAT I) in Slot 3
The NI SCXI-1190 does not have a HVAB connector. Therefore, the
NI SCXI-1127 can operate at the full rating (300 V, CAT II).
Environment
The NI 1357/1358/1359 kit is intended for indoor use only.
Operating temperature............................ 0
°
C to 50
°
C
Storage temperature ............................... –20
°
C to 70
°
C
Relative humidity ................................... 10% to 90%, noncondensing
Measurement Category .......................... II
