Yokogawa RAMC - Manual (Page 25)

<5. LIMIT SWITCHES OPTION /K[]>
5-1
IM 01R01B02-00E-E 10th edition January 01, 2013 -00 All Rights Reserved. Copyright © 2003, Rota Yokogawa
The optional limit switches are available as maximum or minimum type switches. They are proximity switches
according to EN 60947-5-6 (NAMUR). Maximal two switches can be installed. The option (/Wnn) includes the
respective transmitter relay.
These switches have been specified for hazardous area. However, the transmitter relay must be installed
in safe area.
The limit switches are connected to the transmitter relays as indicated in chapter 3.2.
The terminals for the limit switches are on a small board on top of the transmitter case.
Use of 2 standard limit switches (option /K3):
The MIN-MIN and MAX-MAX functions have been integrated at the factory as MIN-MAX switches in the RAMC.
The MIN-MIN or MAX-MAX function is set by adjusting the switching direction of the transmitter relay. The
concerning 2- channel transmitter relays are:
Option /W1B:
KFA5-SR2-Ex2.W
Option /W2B: KFA6-SR2-Ex2.W
Option /W4B: KFD2-SR2-Ex2.W
The following table shows the assignment:
Function Switching direction of transmitter relay *
Channel 1 Channel 2 Channel 1 Channel 2
MIN MAX S1 position I S2 position I
MIN MIN S1 position I S2 position II (ON)
MAX MAX S1 position II (ON) S2 position I
* see following figure for S1 and S2 on transmitter relay.
Use of Fail Safe limit switches (option /K6 ... /K10):
For Fail Safe application only 1- channel transmitter relays are available.
Option /W2E: KHA6-SH-Ex1.W
Option /W2F: 2 x KHA6-SH-Ex1.W
Option /W4E: KFD2-SH-Ex1.W
Option /W4F: 2 x KFD2-SH-Ex1.W
If other transmitter relays are used as the above mentioned types, the transmitter relay has to be applied
as protection technology to ensure functional safety.
Please notice chapter 9.3 "Standard specifications".
For questions regarding protection technology, please consult your YOKOGAWA service center.
5. Limit switches (Option /K[])