11
VERSION 01/2021
ORDER NUMBER DOC2422004
TOPFINISH Bell 1S ECH
2.4.1 IGNITABLE LIQUID COATING PRODUCTS
When using ignitable coating products, the coating system must be equipped with an
on-site extinguishing system. In case of a fire alarm, the high voltage, the air supply and
the product supply must immediately be switched off. If possible, the complete lacquer
supply system must have a grounded setup. In order to keep the discharge energy at the
high-speed rotary atomizer as low as possible, the high-speed rotary atomizer must be
connected to the high-voltage power supply using an attenuated high-voltage line (R =
approx. 50 k /m) with a length of at minimum 5 m.
The discharge energy of this system can be more than 350 mJ; in this case, it is classified
as a type C-L (W < 2 J) or type D-L (W > 2 J) in accordance with EN 50176. There is a risk of
energy capable of acting as an ignition source and a risk of electric shock. The complete
system must be safely grounded before being accessed by people.
With a grounded paint supply system, coating paints, primers, corrosion protection,
structure paints and other coatings with a resistance of > 50 k (in accordance with the
WAGNER/Ransburg scale) are suitable for processing. For highly conductive products
(R < 50 k ) and for products with very high electrical resistance (approx. > 5 M ), the
electrostatic effect has little or no effect, meaning that there is little to no "paint wrap-
around" present on the sprayed object. The suitability of the spray product can be read
from the actual values for the high voltage (kV) and for the spray current (µA).
High kV value, low µA value (no wrap-around) = Paint with excessive electrical
resistance
Low kV-value, high µA-value (no wrap-around) = Excessive conductivity of the paint
With a non-grounded lacquer supply system, coating products with a resistance of < 50 k
can also be used.
2.4.2 NON-IGNITABLE LIQUID COATING PRODUCTS
If water-based lacquers are used, the entire system (high-speed rotary atomizer with
lacquer supply) is brought to high-voltage potential. The system corresponds to type A-NL
(W < 350 mJ) or type B-NL (W > 350 mJ), depending on the structure in accordance with
EN 50348. If the system is classified to Type B-NL, a danger exists through electric shock.
The complete system must be safely grounded before being accessed by people.
In the event of application problems, consult your WAGNER branch and/ or the paint
manufacturer.
2.4.3 CATEGORIZATION OF PRODUCTS
A large portion of stationary electrostatic lacquer spraying systems are currently being
converted to water-based lacquers. At the same time, fire and explosion protection for
these systems can be simplified considerably if the water-based lacquers in use can
demonstrably be considered non-ignitable. Water-dilutable lacquers are in principle
divided into 3 groups:
Green:
Non-ignitable (non-combustible) lacquers
Yellow:
Hard to ignite lacquers
Red:
Ignitable lacquers
As a rule, the lacquer manufacturer determines in which of these three groups a coating
product is classified. In case no information can be obtained in this regard from the lacquer
manufacturer or lacquer supplier, a classification can be performed using the following
formula. Before performing the classification using these formulas, it is mandatory to
request classification from the lacquer manufacturer or lacquer supplier.
