Relay Contact Protection; Selecting The Mains Input Voltage - ABB ZDT–FG Series Installation And Operating Manual

...4 CONNECTIONS

4.2.4 Relay Contact Protection

and Interference Suppression – Fig. 4.3
To reduce the risk of instrument malfunction or incorrect
readings when switching inductive loads, suppression
components must be fitted across the relay contacts.
For a.c. applications, fit a 100R/0.022µF RC suppressor unit
(part no. B9303) as shown in Fig. 4.3A. If the instrument
malfunctions (incorrect readings) or resets (display shows
'88888') when the relays operate, a larger RC network is
required. Contact the manufacturer of the switched device for
details of the RC unit required.
For d.c. applications fit a diode – see Fig. 4.3B. For general
applications use a 1N5406 type (600V peak inverse voltage at
3A – part no. B7363).
Note. For reliable switching the minimum voltage must be
greater than 12V and the minimum current greater than
100mA.
External
L N
AC Supply
A – AC Applications
External
+ –
DC Supply
B – DC Applications
Fig. 4.3 Relay Contact Protection
8
NC C NO Relay Contacts
RC
Suppressor
Unit
Load
NC C NO Relay Contacts
Diode
Load
4.3 Selecting the Mains Input Voltage – Fig. 4.4
Input voltages (230V or 110V) for the main analyzer p.c.b. and
the probe heater supply p.c.b. are selected by two switches
located on their respective p.c.b.'s.
Caution 1. The upper enclosure cover is not
hinged or captive when unlocked.
Caution 2. Both switches must be set to the
same position, otherwise permanent damage to
the instrument may occur.
Unlock and carefully remove
1
the upper enclosure cover. See
2 3 0 V
1 1 5 V
Offer the cover up to the enclosure and reconnect the
5
ribbon cable
6 Refit the upper enclosure cover and lock securely
Fig. 4.4 Selecting the Mains Input Voltage
.
Caution 1
Identify the selector switch
3
on the main p.c.b. and
select the required
mains voltage for the
main p.c.b. See .
Caution 2
Disconnect the front panel
2
ribbon cable at the main p.c.b.
end
Seperate enclosure
and cover
Identify the selector switch
4
on the probe heater
supply p.c.b. and select
the required mains
voltage. See .
Caution 2