Securitron EMB_Series - Manual (Page 8)

PN# 500-23130
Page 8 Rev. C, 03/11
Double Break Wiring
Many installations include a controlled access device such as a digital keypad or card reader.
Such devices typically have a REX (request to exit) input. When dry contacts close on this input,
the entry device will open the lock for the same amount of time that is programmed for entry.
Implementation of the REX input for exit can provide timed exiting. Also, for most entry
controls, the REX input must be used for exiting to avoid an alarm condition at the door.
If the REX input alone is used for exiting, a safety/reliability problem will exist. If the entry
device malfunctions, exit will not be possible and people may be trapped. It is recommended
that double break wiring which is supported by the EMB be used. The EMB normally closed
contacts are used to break power to the fail safe electric lock while the normally open contacts
trip the REX input of the controlled entry device. This releases the lock a second time, hence the
term, "double break". If the controlled entry device fails for any reason, direct exit is still
possible.
The following diagram illustrates a typical double break wiring circuit.
Double Break Wiring:
ELECTRO-MECHANICAL BAR USAGE NOTES:
As the EMB is normally used to permit egress on an electrically secured door, ensure
that all applicable building and fire codes are being followed. Verify installation with
local building and/or fire prevention codes and regulations.
The EMB may not be used on a fire rated door that requires a fire rated latch! The EMB
has no latch. In some instances however, fire doors are permitted on openings where
a fire rated barrier is not required. Use of the EMB should always be verified and
approved through local building code and/or fire prevention agencies.
IF YOU ENCOUNTER PROBLEMS WITH THE INSTALLATION OF THIS PRODUCT,
CALL SECURITRON: 1-800-MAG-LOCK
8. MAGNACARE
 LIFETIME REPLACEMENT WARRANTY
For warranty information visit: www.securitron.com/en/site/securitron/About/MagnaCare-Warranty