Advanced Protection XRL - Manual (Page 11)

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appreciate SPD safety benefits on smoke detectors,
medical equipment, security equipment, etc. Similarly,
some AHJ’s appreciate the financial distress of failed
microelectronic loads.
Dry Contact Option
Two sets of Form C dry contacts are included with the
Dry Contact option. Dry Contacts change state during
inoperative conditions, including loss of power. Any status
change can be monitored elsewhere via Dry Contacts.
A Terminal Block includes two sets of Normally Open
(N.O.) and Normally Closed (N.C) contacts. Both sets of
contacts operate the same. This is shown in Figure 10. A
typical application using a Normally Closed configuration
would connect to one set of the N.C. and Common
terminals. During an inoperative condition, the SPDs dry
contact would change state from normally closed to open.
We generally suggest the Normally Closed configuration
because it will detect a wiring defect, such as cut wire(s),
where N.O. will not.
Please note: Dry Contacts are designed for low voltage
or control signals only.
▪
Maximum switching current is 5A
▪
Maximum switching voltage is 240V DC or AC.
▪
Higher energy applications require additional relay
implementation outside the SPD.
An optional Remote Monitor accessory is available to
provide visual and audible status. The Remote Monitor will
consume one of the two sets of Dry Contacts.
Remote Monitor Accessory Option
A Remote Monitor is available for remote annunciation.
It requires a standalone 120V power source (wall plug
transformer) and uses one set of Form C dry contacts. The
Remote Monitor can be configured to monitor several APT
SPDs simultaneously. Installation is detailed in a separate
document. Contact factory as appropriate.
Retro-fit Into Existing Panel with No Available
Breaker Positions
These can be difficult with limited options.
Follow all applicable Codes:
• Consider consolidating loads in a manner that might free
breaker positions.
• A ten foot tap rule in NEC ® 240.21(B)(1) allows you to tap
the bus as long as the tap conductors are rated at least
10% of the ampacity of the panel. This works well if the
panel is about 600A or less: Tap the bus, run short 6 AWG
leads to the SPD. An SPD with a Disconnect Switch allows
for easier SPD servicing in the future. If the panel starts
getting large (>800A), then the conductor size increases,
which may also become too large to fit into the SPD lugs
or too cumbersome to work with. In that case, consider
tapping the bus per NEC ® 240.21(B)(1). Run appropriate
size conductors to a safety switch fused to 60A. Mount the
SPD immediately adjacent to the safety switch. Connect
SPD to the load side of the safety switch with 6 AWG.
Keep all leads as short as possible.
• Install on Line Side by taking advantage of Type 1 SPD
rating. Consider an SPD with a Disconnect Switch.
• In no-win situations, consider asking the Authority
Having Jurisdiction (AHJ) for guidance. Some AHJ’s
NO
DRY CONTACTS
NC NC C NO C
DRY CONTACT OPTION Figure 10