Burkert Type 0789 - Manual (Page 8)

8
ApplicationConditions
5. applicaTiOn cOndiTiOns
5.1. special conditions
5.1.1. short-circuit protection
Each electromagnet shall be provided on the line with a short-circuit
protection in the form of a fuse designed to meet the magnet starting
current (max. 3 x I
rating
in accordance with IEC 60127-2-1) or a
motor overload trip instantaneous short-circuit and thermal release
(Adjustment to match the pull-in current).
• At very low pull-in currents of the solenoid the fuse with the lowest
current value is adequate according to the stated IEC standard.
This fuse may be mounted in the associated supply unit or must
be connected in series separately.
• The rated voltage of the fuse must be equal to or larger than the
quoted nominal voltage of the magnet.
• The switch-off capability of the fuse cartridge must be equal to or
greater than the maximum theoretical short-circuit current at the
installation location (normally 1500 A).
• In the case of versions PD30 of the solenoid, short-circuit pro-
tection must be assured by the operator.
• In the case of version PD29 of the solenoid, the fuse is installed in
the terminal box of the device.
More detailed descriptions are to be found in the section
“6. Technical data / Safe operation”
.
Fuse ... A
5.1.2. Operation with associated valve body
The solenoid coils Type 77. / 78. may only be operated with a valve
body satisfying the following requirements.
For the valve body, the following materials may be used:
• metal (brass, aluminium, stainless steel) or
• plastics (e,g, polyamide PA 6 GV ...)
5.1.3. manual operation / approximity switch
The solenoid armature can be manually operated via the push
button. The push button may be locked by depressing and turning
by 90°.
As an alternative to manual operation, the solenoid can be equipped
with a proximity switch. The internal code for this version is CF 15.
english
PTB 03 ATEX 1030 X