APL-5 Series Limit Switch Box
Installation Operation & Maintenance Manual
Doc No. : HUMG-APL5-16 Rev0 Page 5 / 13
4.2. Pre-Installation for use in potentially explosive atmosphere
Installation, commissioning, maintenance, repairs and modification work must only be
performed by qualified personnel with extensive knowledge on how to work on explosion-proof
electrical equipment.
Warning : Read this installation and maintenance manual carefully and completely before
attempting to install, operate, or troubleshoot the HKC product
4.2.1. Cable Connection
①Sealing devices must be used and shall be fitted directly at enclosure wall when using
conduit.
②Cable glands shall be suitable for the environment and shall be certified as flameproof if
used in Zone 1 application of IECEx scheme in order to connect outside electric wire.
③Cable glands and conduit to be installed minimum 8 full threads and the length of thread
is minimum 8mm.
④“Warning” : Please be sure that user should select the appropriate cable glands and
minimum 2SQ of wire for fear that the proper using temperature of cable entry and wire
way exceed 70 ℃ or the blanching point is over 80 ℃.
⑤When cable entries or conduit entries are not used, user or installer shall close by certified
blanking elements(stopping plugs) so that the flameproof properties of the enclosure are
maintained.
4.2.2. Groundings
①Always ground the enclosure in accordance with local electric codes. The most effective
enclosure grounding method is a direct connection to earth ground with minimal
impedance. Methods for grounding the enclosure include:
Internal ground connection : The internal ground is located inside the body .
External ground connection : The ground bracket is located on the side of body.
(Min 2SQ wire required)
4.2.3. Special Condition for safe use (“X” marking)
①Electrostatic discharge from window(over 1GΩ) may cause the ignition on the explosive
gas atmosphere. By adapting the conducting window bolts make reduce the risk from
electrostatic discharge.
②Before installation or maintenance products, shut off incoming power and grounding
should be connected.
③The window must only be cleaned with a damp cloth in order to avoid ignition hazard
caused by static electricity.
4.3. Initial inspection
When the user receipts the product, inspect the condition of the product and ensure the name
plate comparing with order sheet.
4.3.1. Remove packing wrap or wooden box carefully. Inspect the product for any physical
damage that may have occurred during shipment.
4.3.2. Check the product specification with product ordered. If an wrong product have been
shipped, immediately report to our coordinator.
