Barksdale L2H User Manual
Page 5
Contacts: color code and function
Lower contacts
Upper contacts
C
= Common
= purple
C
= brown
NC
= Normally Closed Contact
= blue
NC
= orange
NO
= Normally Open Contact
= red
NO
= yellow
Fig. 11: Temperature switch type L2H-…
Contact Protection
The micro switches used are normally suitable for both direct and alternating current operation.
Inductive, capacitive and lamp loads may, however, considerably reduce the life expectancy of a micro
switch and, under extreme circumstances, even damage the contacts.
Depending on the application spark suppression and current limiting is recommended (see succeeding
figures).
Fig. 1: Protection in case of capacitive loads
R1: Protection against starting current
rushes R2,R3: Protection against high
discharge currents
Fig. 2: Lamp load provided with resistance in
series or parallel connection to switch
of condensers
Fig. 3: Protection in case of continuous
current and inductive load by recovery
diode
Fig. 4: Protection in case of alternating
current and inductive load by RC-link
¾“ NPT
Option adjustable
hysteresis (RD)
Adjustment knob
High circuit S2
Adjustment knob
Low circuit S1
22 (0.87)
51 (2.01)
102 (4.016)
Ground screw
11
5
(4
.5
3
)
86
(3.3
9
)
71
(
2
.795)
51
(2.0
1
)
½" NPT
19 (0.756)
ø14.5 (0.43)
63.
5 (
2.
5)
MS
R1
R2
R3
Load
C cable
MS
R
R
MS
MS
U
=
Diode
Load
MS
U
c
Load
R
5
12