
Installation Introduction
66108566001-Rev. B 1-3 SE 3708C
•Up to 16 SE 2814/15 Sensors
•One or two batteries (12 VDC or 24 VDC).
•One or two SE 778 or 778A Annunciator/Control Module(s) powered by the ACU in 800-
series systems.
•One Modem (or similar accessory).
•Several low current locking devices or similar accessories (see below).
As shown in Table 1-1, the SE 3708C is available in four versions, 3708C-112, 3708C-124, 3708C-
212, and the 3708C-224. The 3708C-112 and 3708C-212 are intended for systems with 12-volt locks.
The 3708C-124 and 3708C-224 are to be used for systems with 24-volt locks. Since the batteries
provide lock voltage during power outages, the lock voltage requirement will also determine the battery
voltage requirement. Since the 12-volt 3708C-112/212 and the 24-volt 3708C-124/224 are set and
adjusted to their respective voltages at the factory, they cannot be converted in the field.
At facilities without emergency power systems, the SE 3708C can provide limited emergency power
to maintain access control. The total amount of power it can deliver, however, is fixed, and should not
be exceeded. Doing so may blow fuses, or damage the unit. Therefore, any devices in addition to
those listed above may cause the 3708C to be damaged or operate incorrectly.
As noted, installation personnel should be careful to avoid overloading the system. However, due to
the variety of locks and system configurations available, it is impossible to state exactly how many locks
the SE 3708C is capable of driving. However, for a typical system configuration consisting of one
Access Control Unit controlling several doors, the continuous lock power load should not exceed 4
amps at 12 VDC or 3 amps at 24 VDC. If additional lock power is required, or the system includes two
access control units, some or all lock power will probably need to come from an external power supply
instead of the SE 3708C. It is important to remember that any external power supply must function
independently and must not be paralleled with the SE 3708C.
Consequently, heavy lock power loads, monitoring modules such as motion detectors, glass break
detectors, infrared sensors, and smoke detectors should not be powered by the SE 3708C; they should
have separate power supplies.
1.5 SAFETY INSTRUCTIONS
SAVE THESE INSTRUCTIONS. THIS MANUAL CONTAINS IMPORTANT SAFETY INSTRUC-
TIONS.
CONSERVER CES INSTRUCTIONS. CETTE NOTICE CONTIENT DES INSTRUCTIONS
IMPORTANTES CONCERNANT LA SECURITE.
CAUTION: A BATTERY CAN PRESENT A RISK OF ELECTRICAL SHOCK OR BURN FROM HIGH
SHORT-CIRCUIT CURRENT. OBSERVE PROPER PRECAUTIONS.