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For maintenance access to replace a fuse: flip load bank on its cooling fans side
and remove caster tray – 8 screws (see below figure-21)
Core Unit provides full unrestricted access for electrical wiring from all sides –
top (electrical panel, small fans), bottom (cam-lock connectors, bus bars and
fuses), left and right (resistors, temperature switches, cooling fans, 115VAC
power inlet socket, and control connectors)
1.
Remove all exterior access panels to Load Bank enclosure (including air intake and
exhaust covers).
2. Inspect the intake and exhaust covers. Blow or brush away any noticeable dirt or debris
from air intake and exhaust openings. Ensure covers are functional and free of debris.
Replace any respective panel that is compromised or damaged.
3. Clean any and all dirt and/or debris from the interior of the entire Load Bank. Do not
exceed 40 PSI when using clean, dry, compressed air for blowing and removing dust and
debris.
4. Inspect cooling fans and fan blade, clearing any debris or removing any obstruction. And
fans mounting hardware for tightness. Torque to proper values of tightness as required.
5. Inspect all resistor elements ensuring all hardware is tightened and elements are clear
and free of debris.
6. Inspect all resistors for mechanical and structural integrity and location. Replace any
excessive sagging resistor elements, ceramics and support rods. Replace any and all
broken or cracked termination ceramics, and ceramics on resistor support rods as
required.
7. Inspect all termination ceramic insulators at resistor case ends (both sides) for breaks or
cracks and replace as necessary.
8. Inspect all support rod ceramic insulators for breaks or cracks and replace as
necessary.
9. Inspect the entire inside of the enclosure for loose hardware or loose connections and
tighten to proper torque values as required.
10. Inspect all load and control wiring for signs of insulation failure or breakdown.
11. Inspect for any signs of heat stress on connections and terminals. This could be a sign
of loose hardware or corroded/oxidized connections. Repair and replace connection
hardware as required.
12. Inspect all electrical connections to terminal blocks, main input load bus bars, fuses
mounted to bus bars, all resistor connections for corrosion and oxidation. Clean
connections and replace hardware as required. Tighten as necessary.
13. Inspect all load step contactors. Inspect magnetic contactor coils for oxidation and rust.
Inspect contacts that carry load if pitted, rusted or corroded. Contacts must all move freely
and properly seal when closed. Replace as necessary.
14. When replacing current transformers, mark all leads before removing to ensure proper
phasing of new current transformer. Never leave the secondary of a current transformer
un-shunted.
15. Reinstall all covers ensuring all materials are well in place and all hardware is properly
tightened.
16. Verify cooling fans blades for smooth operation.
