42
MA-Series Service Manual
Mortise Cylinders
Electrically.Locking
Solenoid
Operated
Lock
Rectifier (Not Furnished)
Door Connector
(not furnished)
Install
varistor
here
if used
(not furnished)
Transformer
(not furnished)
Switch
(not furnished)
12 or 24V AC
110V AC
MA851 Electrically Locked (Fail Safe):
Outside trim is continuously locked electrically. The latchbolt is retracted by a key outside or by the knob/lever inside.
Switch or power failure allows the outside knob/lever to retract the latchbolt. The auxiliary latch deadlocks the latchbolt
when the door is closed. The inside knob/lever is always free for immediate exit.
MA881 Electrically Unlocked (Fail Secure):
Outside trim is unlocked electrically. During switch or power failure, the latchbolt is retracted by a key outside or by
knob/lever inside. The auxiliary latch deadlocks the latchbolt when the door is closed. The inside knob/lever is always
free for immediate exit.
Electrical Requirements:
Voltage: 12V DC +/- 10%
Operating Temperature: Max +151° F, Min. -31° F
Operating Current: .42 Amps
Holding Current: .135 Amps
Voltage: 24V DC +/- 10%
Operating Temperature: Max +151° F, Min. -31° F
Operating Current: .21 Amps
Holding Current: .135 Amps
Typical Installation:
All installations should be in accordance with local electrical codes and National Electrical Code NFPA #70. It is
recommended that each lock have its own 12 or 24 volt transformer. Be sure to select the proper transformer for the
lock. Two or more locks may be operated in parallel from a single transformer provided it has the necessary current
rating. DO NOT connect locks in series from a higher voltage rated transformer. Damage to locks may occur if they
connect to a supply circuit that also contains electromagnetic devices. The transient voltage must be suppressed at
the equipment producing them before connecting the locks to a circuit. A varistor rate at 35 volts (at peak current) may
be used for transient voltage protection.
