Page 20 - PBL71 OI/AXM630-EN AZTEC 600 SS (WIRO)

Aztec 600 ISE ammonia and fluoride
Single-stream ion-selective analyzers
3.5.3 Ethernet Connection
3 Installation
3.5.4 Alarm Relay Contact Protection and Interference Suppression
EHGC
F
B
D
J
A
External AC Supply
NC C NO Relay Contacts
LN
A – AC Applications
NC C NO Relay Contacts
Diode
+–
B – DC Applications
R
C
Load
External DC Supply
Load
Fig. 3.7 Ethernet Connections
The Ethernet gland is different from the other connections to accommodate an RJ45 plug:
1. Referring to steps 1 and 2 in Section 3.5.2, page 15, open the electronics section door and remove the transparent cover plate.
2. Referring to Fig. 3.7:
a. Slide retaining clip A off blanking plug B and remove the blanking plug.
b. Fit cable gland C and secure using nut D.
c. Remove gland cover E and route cable F through
it.
d. Fit the rubber split-bush G and split-washer H over the cable.
e. Route the cable through cable gland C and into the enclosure case.
f. Plug the RJ45 connector J into the Ethernet RJ45 connector socket on the application board (see Fig. 3.5, page 14 for location details) and tighten gland nut E.
3. Referring to step 12 in Section 3.5.2, page 15, refit the transparent cover plate and close and secure the electronics section door.
Fig. 3.8 Relay Contact Protection
If the relays are used to switch loads on or off, the relay contacts can become eroded due to arcing. Arcing also produces RFI that can cause analyzer malfunctions and incorrect readings. To minimize the effects of RFI, arc suppression components are required; these are resistor / capacitor networks for AC applications or diodes for DC applications. These components can be connected across the load.
Maximum relay ratings are:
 250 V, 5 A AC, 1250 VA (non-inductive)  30V,5ADC150W
For AC applications the value of the resistor / capacitor network depends on the load current and inductance that is switched. Initially, fit a 100R / 0.022 μF RC suppressor unit. If the analyzer malfunctions the value of the RC network is too low for suppression and an alternative value must be used.
For DC applications fit a diode – see Fig. 3.8. For general applications use an alternative IN5406 type (600 V peak inverse voltage at 3 A).
16
OI/AXM630–EN Rev. J
Note. For reliable switching the minimum voltage must be >12 V and the minimum current >100 mA.