APC PMH3XS-B ユーザーズマニュアル

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18
Installation and Operation Manual 
Dry Contacts
The SurgeArrest
®
 series SPDs come standard with dry contacts. The 
connection for the dry contacts is located on the back of the diagnostic display 
panel (lower right corner). The dry contacts are 3-position, Form “C” type with 
Normally Open, Normally Closed and Common connections. In the unpowered 
state the contact is closed between terminals NC and COM. This is also the 
alarm condition. The opposite state, closed between terminals NO and COM, 
indicates that power is on to the unit and that no alarm condition exists (See 
Table 5). These contacts can be used for remote indication of the SPD’s 
operating status to a computer interface board or emergency management 
system. Also, these contacts are designed to work with the SPD remote 
monitor option described below.
The dry contacts are designed for a maximum voltage of 24 Vdc / 24 Vac and a 
maximum current of 2 A. Higher energy applications may require additional 
relay implementation outside the SPD. Damage to the SPD’s relay caused by 
use with energy levels in excess of those discussed in this instruction bulletin 
are not covered by warranty. For application questions, contact APC Technical 
Support at 1-800-800-4272.
Care must be taken in installing the dry contact wiring because the terminals 
are on a moving door. Avoid the door hinge, any switches, and the high voltage 
areas of the enclosure when routing the wiring. To avoid the door hinge, tie 
wrap any dry contact wiring to the existing cable harness which crosses the 
hinge. Once the dry contact wiring is secured on a non-moving point of the 
enclosure, it is the user’s responsibility to maintain at least 1.0 in. (25 mm) 
separation between 600 Vac rated dry contact wiring and the power wiring in 
the enclosure.
Figure 8:
Rear of Diagnostic Circuit Board
Dry 
contacts
RJ45
Connectors
Surge counter
reset switch
(white)
DANGER
HAZARD OF ELECTRIC SHOCK, EXPLOSION, OR ARC FLASH
• Use 600 Vac rated dry contact wiring.
• Dry contact wiring must have less than 1/16 in. (1.6 mm) exposed wire 
from the dry contact block.
• Maintain at least 1.0 in. (25 mm) separation between dry contact wiring 
and the power wiring in the enclosure.
Failure to follow these instructions will result in death or serious injury.
Table 5:
Dry Contact Configuration
Alarm Contact Terminals
Contact State with Power Removed
NC
Normally closed
COM
Common
NO
Normally open
Operation