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Rev. A.5, 8/03 Page- 14
compatibility. Dress covers are available in clear aluminum, satin black aluminum, polished
stainless and polished brass finishes.
Double dress covers are also available for installations on double doors. In this case, the cover
fits over two locks so long as they are not separated by more than 2" (50mm). Double dress
covers have all the advantages mentioned above and in addition produce the appearance of a
single device which inside is really two. Consult the catalog for dress cover part numbers.
2.8 TAMPER PROOFING THE MAGNALOCK
In situations where vandalism is expected, the Magnalock should be protected from tampering.
The magnet itself is inherently tamper-proof being totally sealed. The magnet mounting screws
are vulnerable in that the magnet can be dismounted if the screws are loosened. The allen
holes on the screws can be filled with a potting compound, such as Devcon, or silicone.
Alternately, the entire hole in the magnet where the screw heads fit could be filled. Butyrate
caps are supplied to close the mounting holes. These provide some tamper proofing as they
can't be removed by hand, but can be pried out with a tool. Regarding the strike plate mounting
screw, it is covered by the strike when the magnet is energized. If tampering is anticipated
when the door is open, the screw socket head may be filled.
Another possibility is that
Securitron inventories special tamper proof screws for both
magnet and strike mounting. These screws are identical allen head types except that it requires
a special key to install and remove the screws. It is unlikely that a vandal would have access to
this type of key. Securitron optionally supplies the tamper proof screw sets with keys both in the
form of a manual allen wrench and in a bit key usable with a drill.
3. ELECTRICAL INSTALLATION
3.1 GENERAL ELECTRICAL CHARACTERISTICS
The Magnalock constitutes a low current electric load. Owing to internal circuitry, the
Magnalock does not show the normal characteristics of an electromagnetic or other inductive
load. Inductive kickback is suppressed, so arcing across switch contacts need not be a
concern. This suppression also protects nearby access control or computer equipment from
possible interference. The circuitry performs the additional functions of canceling residual
magnetism ("stickiness" on release) and accelerating field collapse so that the Magnalock
releases nearly instantly when power is removed. Electrically speaking, the load is nearly pure
resistive in nature although there is a modest capacitive component which depends on the
series. The following chart shows the current draw for each version and the degree of internal
capacitance.
32 @ 12V 32 @ 24V 34 @ 12V 34 @ 24V 62 @ 12V 62 @ 24V 82 @ 12V 82 @ 24V
CURRENT 300 mA 150 mA 350 mA 175 mA 250 mA 125 mA 350 mA 175 mA
CAPACITANCE 0 0 0 0 30 Mfd 15 Mfd 30 Mfd 15 Mfd
Capacitance can be an issue if very sensitive switch contacts are used to control the Magnalock
(such as a low current reed switch). A capacitive load includes some inrush current which can
stress these contacts. Note however that the problem is diminished when the Magnalock is
mounted some distance from the control switch as the interconnecting wiring adds a series
resistance to the circuit which sharply limits the inrush.
3.2 STANDARD LOCK
For operation, DC voltage must be provided to the lock. The red wire receives +12VDC or
+24VDC, and the black wire, 0V (negative).
If the lock is connected with reverse polarity, it
will not function at all. The voltage source may be regulated, filtered or pulsating DC
(transformer + bridge rectifier).
Half wave pulsating DC generated by a transformer and
single diode will not properly operate the Magnalock. An exact voltage level is not
necessary. Less than standard voltage will proportionately reduce holding force but will cause
no harm. Overvoltage up to 30% is acceptable.
The model 34, 62 and 82 series Magnalocks are
dual voltage units. This means that you can
apply either 12 or 24 volts to the same unit and it will operate equally well. Dual voltage
Magnalocks are
auto-switching which means that you still apply power to the red and black