Buhler Nivotemp NT64, Инструкция по установке и эксплуатации

Страница: 18 / 29

Bedienungs- und Installationsanleitung
Installation- and Operation Instruction
Nivotemp NT64 / Nivovent NV74
18
BX100020 05/2014 Art. Nr. 9032037
Contact protective circuits for reed switches
Under direct current voltage a recovery diode per figure A should be connected parallel to the contact.
Under alternating current voltage an RC circuit per Figure B and Table 1 should be connected parallel to
the contact.
A
B
contact
load
Diode
+
_
contact
load
RC-network
R
~
C
~
Voltages and currents
All Bühler level contacts with reed switch can switch minimal Switching voltages of 10 µV and minimal
switching currents of 1 µA.
The maximum values specified for the respective contact types apply.
Level contact with reed switches can therefore be used for SPS applications as well as for high loads
(within the maximum limits) without hesitation.
Contact material
All reed switches in Bühler level contacts use rhodium as the contact material for the actual contact areas.
Compared to gold, rhodium is significantly more wear resistant to contact sparks and the contact blades
are also less likely to burn and adhere. Gold is only used as a support material for the ensuing rhodium
layer. The contact resistance of rhodium coated contact areas is no different than gold coated. Based on
the undeniable advantages of rhodium coating for contact areas, reed switch manufacturers phased out
gold plated contacts years ago.
VA
24
48
110
230
10 25 50 75 100
R/Ohm
C/µF
R/Ohm R/Ohm R/Ohm R/Ohm
C/µF C/µF C/µF C/µF
22
120
470
470
0,022
0,0047
0,001
0,001
1
22
120
470
0,1
0,022
0,0047
0,001
1
1
22
120
0,47
0,1
0,022
0,0047
1
1
22
120
1,0
0,47
0,047
0,022
1
1
22
120
1,0
0,47
0,1
0,022
Voltage at contact V