Advanced Protection HPS - Manual (Page 10)

10
MAINTENANCE
SPDs require minimal maintenance. We recommend periodic
inspection of diagnostic indicators to ensure proper operation.
We also recommend keeping the SPD clean as appropriate.
Fuse Replacement
Fuses must be replaced with exact fuse included. These
are special fuses and not typical fuses. Note that fuses
are generally opened by failed modules. Modules can be
removed and checked for short circuit with ohm-meter. Any
reading other than open circuit suggests a failed module. Any
reading <200 Ω positively confirms a failed module. Contact
APT Technical Support as appropriate.
Module Removal & Replacement Instructions
Disconnect power to the SPD. Using an allen wrench, remove
the bolts on both ends of the module, and pull the module
out. Make careful note of the location and part number of
each module removed, as this part number is not referenced
anywhere else on the SPD.
The module(s) should only be replaced with a new module
bearing the same part number as the module(s) being
removed. Replace with a new module by reversing the
procedure. Torque bolts to 65 inch lbs., power up the SPD and
verify the green module LED is lit and all alarms have cleared.
Display Replacement
The display is field replaceable. Service should only
be performed by qualified persons. Deenergize SPD,
confirm with appropriate measurement equipment and
discharge internal capacitance to ground. Mark locations
and carefully disconnect diagnostic cables, contacts,
connecting conductors, etc. Unbolt display and replace.
Reinstall in reverse.
Note that a sealing gasket between the display and the
enclosure is a key component ensuring weather resistance.
Replace the gasket whenever the display is removed.
Diagnostic Board Removal & Replacement Instructions
Disconnect power to the SPD. Remove the board
from the standoffs. Remove the connectors one at a
time from the existing board and insert them into the
appropriate connector on the replacement board. Install
the replacement board onto the standoffs.
Troubleshooting & Service
Please contact us for any service related issues. We want
to take care of any problems.
Quality SPDs are designed and tested to withstand severe
duty. However, there are various electrical anomalies that
SPDs cannot protect against. These are generally Sustained
Overvoltages also known as Temporary Overvoltages
(TOVs). In this context, Sustained Overvoltages may be only
a few cycles. Failed SPDs tend to be symptoms, not root
causes. A failed SPD should be treated as a ‘canary in the
coalmine’ suggesting further investigation as there may be
a larger issue at play. Regardless of cause, SPDs attempt
to protect their load until failure.
As noted above, the single largest ‘killer’ of SPDs is
reference to ground issues. If the SPD shows problems on
startup, there is reasonable chance of bonding/grounding/
misapplication issue. This permanently damages the unit.
If not corrected, it will happen again.
Table 3:
MODULE REMOVAL & REPLACEMENT
Order # Part Description
MA120 120VAC Module with Indicator LED
MA120CX 120VAC Module with Indicator LED
MA120CL 120VAC Module with Indicator LED
MA120NI 120VAC Module with NO Indicator LED
MA120NICX 120VAC Module with NO Indicator LED
MA120NICL 120VAC Module with NO Indicator LED
MA240 240VAC Module with Indicator LED
MA240CX 240VAC Module with Indicator LED
MA240CL 240VAC Module with Indicator LED
MA240NI 240VAC Module with NO Indicator LED
MA240NICX 240VAC Module with NO Indicator LED
MA240NICL 240VAC Module with NO Indicator LED
MA277 277VAC Module with Indicator LED
MA277CX 277VAC Module with Indicator LED
MA277CL 277VAC Module with Indicator LED
MA277NI 277VAC Module with NO Indicator LED
MA277NICX 277VAC Module with NO Indicator LED
MA277NICL 277VAC Module with NO Indicator LED
MA347 347VAC Module with Indicator LED
MA347CX 347VAC Module with Indicator LED
MA347CL 347VAC Module with Indicator LED
MA347NI 347VAC Module with NO Indicator LED
MA347NICX 347VAC Module with NO Indicator LED
MA347NICL 347VAC Module with NO Indicator LED
Table 4: FUSE-ALL SERIES
Order # Part Description
7294 APT 100-2 Fuse
Tip: Visually confirm N-G bonding. Be aware that a voltmeter
measuring N-G can be misleading. For example, N-G voltage
could read 0V because neutral and ground are at the same
potential by happenstance, not because they are bonded.
Visually confirm bonding.
Tip: Experience indicates that regulation-challenged generators
can cause Sustained Overvoltages, as well as ungrounded
generators, and/or unusual load transfer systems.