Larson Electronics EPS-25A Instructions

This device complies with requirements of Underwriters Laboratories, Inc. for use in hazardous
locations, as listed on the device when used with suitable enclosures.
WARNING: To avoid risk of explosion, all flat machined surfaces must be kept clean and free from
scratches, dents, debris, paint, and corrosion. The flat machined surfaces are explosion proof joints, and
must be clean and undamaged on both the enclosure and cover.
INSTALLATION
1. The surfaces of the flat ground joint are precision machined to insure an explosion proof joint
and must be protected from scratches or damage during installation.
2. When switch is mounted in the enclosure, it must be mounted to agree with cover indication of
operation. That is, when the cover indicates ON, the switch must be in the ON condition.
3. Before the cover is installed, the flat ground joint surface must be thoroughly wiped clean of any
dirt, grit, or other foreign substances and a light thin coating of lubricant placed on the joint to
prevent possible corrosion.
The joint between the box and the cover has been made accurately to .0015" to prevent the
passage of this accuracy is destroyed.
4. ALL cover screws must be installed with at least five full threads engaged and must be securely
tightened. All cover openings must be closed with a suitable cover.
5. Gaskets must not be added to these devices. Only gaskets designed for and permanently
installed in these devices may be used.
6. In accordance with the hazardous location information specifying Class and Group listing
marked on the device, sealing fittings must be added that will comply with requirements in the
latest issue of the Canadian Electrical Code or National Electrical Code and any special
requirements that are stated in the instruction sheet with the enclosure.
MAINTENANCE
Before removing the cover from any such device for inspection or maintenance, the power supply circuit
must be OFF.
WARNING: To prevent risk of explosion, hammers and prying tools must not be used to remove covers
off enclosures. Damage to the explosion proof flat machined surfaces on cover and enclosure may
result. Handle covers carefully. Do not place them on surfaces that might damage or scratch the flat
machined surfaces.
Before replacing the cover, after it has once been removed, the flat ground joint surfaces must be
cleaned as described in step 3 under installation.
WARNING: To prevent risk of explosion, replace devices if the flat machined surface is damaged,
scratched, dented, or corroded. Field rework of flat machined surfaces is not possible.
EPS-25A
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