For motors with degree of protection IP56, IP65 or IP66, the drain plugs must remain at closed position, being opened only during the motor maintenance
procedures.
"Automatic" rubber drain plugs are designed for one use only and cannot be reused. If any drain plug is removed for any purpose, it must always be
replaced by a new one.
The drain system of motors with Oil Mist lubrication system must be connected to a specific collection system.
The drain plugs of explosion proof motors cannot be removed during installation and maintenance procedures.
When provided with a breather-drain to certificate IECEx CSA 12.0005U, the motors are limited to Groups IIB, IIC and IIIC, an ambient temperature of
-55 °C to + 40 °C, temperature classification T5 to T2, and have a degree of protection of IP6X (for group IIIC).
Do not cover or block the motor ventilation openings. Ensure a minimum clearance of ¼ of the diameter of the air intake of the fan cover from the walls.
The air used for cooling the motor must be at ambient temperature, limited to the temperature range indicated on the motor nameplate (when not indicated, -20 °C
to +40 °C must be considered).
Motors installed outdoors or in the vertical position require the use of additional shelter to protect them from water; for instance, use of a drip cover.
To prevent accidents, ensure that the grounding connection has been performed according to the applicable standards and that the shaft key has been securely
fastened before the motor is started.
Connect the motor properly to the power supply by means of safe and permanent contacts, always considering the data informed on the nameplate, such as rated
voltage, wiring diagram, etc.
When motors are supplied with flying leads, they must be suitably connected to an appropriate terminal box required for the use condition (type of protection).
When using terminals, all wires that form the stranded cable must be fastened inside the sleeve. The insulation of the accessories cables must be kept up to 1 mm
from the connector connection point.
When provided with terminal blocks marked with "W-A12", "W-B12 (160V)" or "W-B12 (500V)", the following characteristics must be respected:
Characteristic
Voltage
Current
Conductor cross-section
Number of cables per terminal connection
Connection torque
Service temperature
ATEX marking/certificate
IECEx marking/certificate
For power cables and grounding system connections and terminal box assembly, the tightening torques indicated on Tables 2 and 3 must be respected.
Type of protection
of enclosure
Ex db
Terminal Box Cover
Ex db eb
Ex db
Ex db eb
Locking bolt for connection clamp
Ex ec
Ex tb
Ex tc
Ex eb
Thread
Material
Plastic
Metric
Metallic
Thread
Material
Plastic
NPT
Metallic
For power cables, switching and protection devices dimensioning, consider the rated motor current, the service factor, and the cable length, among others.
For motors without terminal block, insulate the motor terminal cables by using insulating materials that are compatible with the insulation class informed on the
nameplate. The minimum insulation distance between the non-insulated live parts themselves and between live parts and the grounding must respect the Table 4.
Voltage
U ≤ 440 V
440 < U ≤ 690 V
690 < U ≤ 1000 V
1000 < U ≤ 6900 V
6900 < U ≤ 11000 V
11000 <U ≤ 16500 V
Take the required measures in order to ensure the type of protection, the EPL and the degree of protection indicated on the motor nameplate:
- unused cable inlet holes in the terminal boxes must be properly closed with certified plugs;
- components supplied loose (for example, terminal boxes mounted separately) must be properly closed and sealed;
The cable entries used must be fitted with components (such as, cable glands and conduits) that meet the applicable standards and regulations for each country.
For "Ex db" motors, the conduit entries are permitted only for electrical equipment of group II.
The fixing elements mounted in the threaded through holes in the motor enclosure (for example, the flange) must be properly sealed, with the products listed in
item 5, to ensure the degree of protection indicated on the motor nameplate.
The motor must be installed with overload protection devices. These protection devices can be integrated to the motor (such as thermistors in the windings) or external protection
devices, where the motor load is monitored by the nominal current. For three-phase motors, it is recommended to install a phase failure protection device. Motors driven by
variable frequency drives must have their winding thermal protections connected. For other starting methods, the use of the thermal protections is optional. For "Ex ec", "Ex db",
"Ex db eb", "Ex tb" and "Ex tc" motors: all thermal protections (RTDs, bimetal thermal protectors and thermistors for stator protection) used in the motor protection circuit can be
connected via a standard industrial controller located in a safe area.
For "Ex eb" motors: all thermal protections (RTDs, bimetal thermal protectors and thermistors for stator protection) used in the motor protection circuit must be separately
protected by the use of an intrinsic safety supply that ensures the minimum EPL Gb level of protection.
Ensure the correct operation of the accessories (brake, encoder, thermal protection, forced ventilation, etc.) installed on the motor before it is started.The temperature limits for
alarm and tripping of the thermal protection can be defined according to the application, however they may not exceed the values shown in Table 5.
4 | Electric motors for explosive atmospheres
Table 1 - Terminal block type designation
W-A12
Up to 160 V
Max. 15 A
0,3 to 2,5 mm²
2x1 mm²
Table 2 - Tightening torques for fixing elements [Nm]
Component
Class 8.8/12.9
Class A2-70 / A4-70
Grounding
Terminal block
Locking bolt for power cables
Terminal box cover
Grounding
Terminal block
Terminal block fixing bolts
Table 3 - Tightening torques for cable glands and plugs [Nm]
M16
M20
3 to 5
3 to 5
40 to 50
40 to 50
NPT 1/2"
NPT 3/4"
-
5 to 6
40 to 50
40 to 50
Table 4 - Minimum insulation distance (mm)
Terminal block type designation
W-B12 (160 V)
Up to 160 V
Max. 15 A
0,3 to 4 mm²
2x1,5 mm²
0,5 to 0,7 Nm
-20 °C to + 80 °C
II 2G Ex eb IIC Gb / I M2 Ex eb I Mb / PTB 06 ATEX 1078 U
Ex eb IIC Gb / Ex eb I Mb / IECEx PTB 17.0014U
M4
M5
M6
-
3,5 to 5
6 to 12
14 to 30
-
3,5 to 5
6 to 8,5
14 to 19
1,5 to 3
3 to 5
5 to 10
10 to 18
1 to 1,5
2 to 4
4 to 6,5
6,5 to 9
1 to 1,5
2 to 4
4 to 6,5
6,5 to 9
-
3 to 7
4 to 8
7 to 11
-
-
-
-
3 to 5
4 to 8
8 to 15
1,5 to 3
3 to 5
5 to 10
10 to 18
1 to 1,5
2 to 4
4 to 6,5
6,5 to 9
-
3 to 5
5 to 10
10 to 18
M25
M32
6 to 8
6 to 8
55 to 70
65 to 80
NPT 1"
NPT 1 1/2"
6 to 8
6 to 8
55 to 70
65 to 80
Type of protection of the enclosure
Ex eb / Ex db eb
6
10
14
60
100
-
M8
M10
M12
M14
28 to 60
45 to 105
75 to 110
28 to 40
45 to 60
75 to 100
28 to 40
45 to 70
10 to 18
15,5 to 30
5 to 9
10 to 15
-
-
2 to 6
6 to 10
-
18 to 30
25 to 40
30 to 45
28 to 40
45 to 70
10 to 18
15,5 to 30
28 to 40
45 to 70
75 to 110
M40
M50
6 to 8
6 to 8
80 to 100
100 to 120
115 to 140
NPT 2"
NPT 2 1/2"
6 to 8
6 to 8
100 to 120
115 to 140
150 to 175
Ex ec / Ex db / Ex tb / Ex tc
W-B12 (500 V)
Up to 500 V
Max. 20 A
0,3 to 4 mm²
2x1,5 mm²
M16
M20
115 to 170 230 to 330
115 to 170 225 to 290
-
115 to 170
-
-
30 to 50
50 to 75
-
20 to 30
-
-
-
-
-
-
-
35 to 50
-
-
115 to 170
-
-
30 to 50
50 to 75
115 to 170
-
M63
M80
6 to 8
6 to 8
160 to 190
NPT 3"
NPT 4"
6 to 8
6 to 8
200 to 240
4
5,5
8
45
70
105