66
UTD.123.2019-10.00_EN
11.5 - Pressure switch with flameproof enclosure Ex d
II 2G Ex db IIC T4 Gb
II 2D Ex tb IIIC T135 Db IP66
ATTENTION: In presence of brake PB series and application of ATEX 2G, 2D and 3G, 3D, the pressure
switch is always necessary as a safety device. The equipment on which the brake is installed can be
operated only when the detection of a pressure value higher than the set one confirms that the brake
is released.
General technical specifications
:
- Flameproof enclosure: alluminium alloy, copper free, polyurethan paint
- 1x SPDT, single pole double throw hermetically sealed, argon gas filling
- Electrical rating (resistive load):
AC: 250 V, 15 A
DC: 24 V, 2 A, 220 V, 0,5 A
- Process connection: 1/4-18 NPT-female
- Electrical connection: 1/2-14 NPT-female
- Permissible ambient temperature range: - 30°C ... +70°C
- Working pressure range: 0 - 350 bar
- Setting range: 20 - 220 bar (see note about pressure setting value)
- Protection degree: IP66 per IEC/EN 60529
- SIL2 (Safety Integrity Level)
Pressure switch setting:
The pressure switch is supplied by Rossi already set to the nominal value, see below. This setting refers to
the comprehensive range of PB brakes, however it is possible to obtain several setting values, if need be.
Nominal setting pressure value, rising pressure
(operation pressure or set point) =
100 bar
Actual Setting Pressure = from 98 to 102 bar
Resetting pressure, failing = min 92 bar
Electrical connection:
Follow the instructions stated in the installation and maintenance manual supplied by the manufacturer.
When commissioning the gear reducer
Check that pressure in brake supply circuit is suitable and sufficient to exceed the operating threshold
(set pressure).
During the normal operation
If, during brake opening (gear reducer starting transient), a longer time should be necessary to achieve the
operating pressure, it is allowed the running of brake for Max. 5 seconds assuming that supply pressure is
higher than pressure of brake opening end ("p" pressure according to technical sheet).
Installation
:
The pressure switch is supplied by Rossi and installed directly on a port of a T-connection fitted to the
brake, the other port of the T-connection carries a 1/4" G thread for the brake release pipe.
The standard configuration foresees the supply of the switch in VERTICAL position (see fig. 11.5.1), but in
presence of application overall dimensions, it is possible to have an HORIZONTAL mounting (see fig. 11.5.2).