Installation, Operation and Maintenance Manual
8221 RevD 08-18
9
FIGURE 7: LEADS
Connecting Optional Form C Dry Contact & Audible Alarm
Three (3) 3’ (~1m) 18 AWG wires are included through the nipple with this option. See Figure 6. (These
are smaller than the 10 AWG SPD conductors.) Gray is Common, Blue is Normally Open and Red is
Normally Closed when energized in its expected installation. (When Not energized, the SPD is no
longer in its ‘Normal’ state and contacts will be reversed.) We generally recommend the Normally
Closed configuration because it detects disconnected or failed wiring whereas Normally Open does
not.
If the dry contacts are not utilized, insulate lead ends, coil and secure. Audible Alarm will still function
correctly.
The contact is rated 250V, 5A. Higher energy applications require supplemental relaying. This option
monitors suppression element condition and is not intended for use as phase loss or phase detection
monitoring.
NORMAL OPERATION
Green LED Indicator
The LED indicator illuminates when the SPD is energized and operating correctly. Indicator operation:
Every suppression element is connected via logic to the green LED. Should any suppression element
fail, the green LED will extinguish.
Power
Leads
Dry
Contact
Leads
Blue
Grey
Red
•
Normally Closed (suggested): Use Gray and Red
•
Normally Open: Use Gray and Blue