42MA-Series Service ManualSolenoidOperatedLockRectifier (Not Furnished)Door Connector(not furnished)Installvaristorhereif used(not furnished)Transformer(not furnished)Switch(not furnished) 12 or 24V AC 110V ACElectrically LockingMA851 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 latchboltwhen 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 byknob/lever inside. The auxiliary latch deadlocks the latchbolt when the door is closed. The inside knob/lever is alwaysfree for immediate exit.Electrical Requirements:Voltage: 12V DC +/- 10%Operating Temperature: Max +151° F, Min. -31° FOperating Current: .42 AmpsHolding Current: .135 AmpsVoltage: 24V DC +/- 10%Operating Temperature: Max +151° F, Min. -31° FOperating Current: .21 AmpsHolding Current: .135 AmpsTypical Installation:All installations should be in accordance with local electrical codes and National Electrical Code NFPA #70. It isrecommended that each lock have its own 12 or 24 volt transformer. Be sure to select the proper transformer for thelock. Two or more locks may be operated in parallel from a single transformer provided it has the necessary currentrating. DO NOT connect locks in series from a higher voltage rated transformer. Damage to locks may occur if theyconnect to a supply circuit that also contains electromagnetic devices. The transient voltage must be suppressed atthe equipment producing them before connecting the locks to a circuit. A varistor rate at 35 volts (at peak current) maybe used for transient voltage protection.Electrical Locks