Bernard Controls SQX Series User Manual

5
Screws of explosion-proof actuator body must be of a minimum 8.8 quality grade or made of
stainless steel with a minimum 70 daN/mm2 tensile strength. In case of use in explosive dust
atmosphere, check that cover tightness gaskets are intact and make sure not to degrade the gas-
kets while closing the cover. Cable entries shall provide a level of protection equal or higher than the
one indicated on the actuator identification plate. The user shall ensure a regular cleaning of the product
housing to avoid dust build-up.
Overheating
A motor thermal protection switch is (refer to actuator electric diagram) integrated into the motor
control circuit in order to switch off the motor power supply in case of overheating conditions. This
protection is mandatory to respect maximum surface temperatures.
Cable entries
Check that cable glands are used and wiring done according to the explosion-proof equipment standards ;
take a special care of the compatibility between the cable diameter and the cable gland size. If one
of the cable entries is not used, seal it with a certified metal plug and without adapter.
If an adapter is necessary to fit a cable gland, only one is allowed by cable entry and use a certified one.
The actuator is delivered with a yellow sticker, in the connection compartment, that obstruates the cable
entries. The danger symbol
and a notice warns the installer of the obligation to equip each cable entry
with a certified plug or cable gland.
For cable gland and plug take care of the marking:
ATEX : Exd (or Exe in case of an increased safety « e » connexion
compartment)
IECEx : Exd (or Exe in case of an increased safety « e » connexion
compartment)
IEx : Brazilian certification Exd.
For Exd box, the thread type is indicated in the connection box to avoid confusion (NPT or ISO).
If the ambiant temperature exceeds 60°C, consider an additional 10°C at the cable entry. I.e, at a maximum
ambiant temperature of 70°C, the temperature at the cable entry will be 80°C.
Terminal compartment with double double-sealing protection and volume < 2 liitres.
Wiring
Maximum acceptable voltage for the power supply terminal (M4) is 690V and 160V for control terminals
unless otherwise specified on the wiring diagram. Connection is done with isolated and crimped ring tongue
terminals. The maximum cable section is 6mm2 for the power supply (M4) and 4mm2 for controls (M3).
An external earth rod allows connection to the earth (4 mm
2
for stranded, 6mm
2
single wire, on request up
to 35mm
2
). Make sure to wire both internal and external groundings.
Water-proofness
Because the NPT cable gland thread is not IP68, it’s necessary to mount it with a thread sealant for ex: Loctite
577 (Henkel). In case of ISO thread, sealing is assured by an O ring or by a thread sealant as noticed above.
Please note : For Exd enclosure, thread type (NPT or ISO) is indicated in the connection box to avoid any mistake.

Bernard Controls SQX Series Specifications

General

Brand	Bernard Controls
Model	SQX Series
Category	Controller
Language	English