3.1.2 Supply air pressure
The required supply air pressure depends
on the bench range and the operating direc-
tion (fail-safe action) of the actuator. The
bench range is indicated on the nameplate
as spring range or as signal pressure range.
Actuator stem extends:
required supply air pressure =
upper bench range value + 0.2 bar,
at least 1.4 bar.
Actuator stem retracts:
The required supply air pressure for tight-
closing valves is estimated on the basis of
the maximum signal pressure p
st
max
:
p
st max
= F +
d
2
⋅
π
⋅
∆
p
4
⋅
A
[bar]
d
= Seat diameter [cm]
∆
p = Differential pressure across the valve [bar]
A
= Actuator area [cm2]
F
= Upper bench range value of the actuator [bar]
If there are no specifications, calculate as
follows:
Required supply air pressure = upper
bench range value + 1 bar
3.2 Electrical connections
As far as the electrical installation of
the device is concerned, the relevant
national regulations governing the
installation of electrical equipment
and the national accident preven-
tion regulations of the country of
destination must be adhered to.
In Germany, these are the VDE regu-
lations and accident prevention
regulations of the employer’s lia-
bility insurance.
For installation in hazardous areas,
the following standards apply: EN
60079-14: 1997; VDE 0165 Part
1/8.98 "Electrical apparatus for ex-
plosive gas areas" and EN 50281-
1-2: VDE 0165 Part 2/11.99 "Elec-
trical apparatus for use in the
presence of combustible dust".
For intrinsically safe electrical ap-
paratus that are certified according
to the Directive 79/196/EEC, the
data specified in the certificate of
conformity apply for connection of
intrinsically safe circuits.
For intrinsically safe electrical ap-
paratus that are certified according
to the Directive 94/9/EC, the data
specified in the EC-type examin-
ation certificate apply for connec-
tion of intrinsically safe circuits.
Note:
It is absolutely necessary to
keep to the terminal plan specified
in the certificate. Reversal of the elec-
trical connections may cause the ex-
plosion protection to be ineffective!
Do not tamper with any painted
screws inside or on the case.
EB 8382-1 EN
25
Connections
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