Kidde VM-1 Technical Reference Manual

Chapter 5: Installation
P/N 3101890-EN • REV 006 • ISS 21JUN18 93
Removing the plug re-establishes connection to the premises telephones. Inserting the plug opens the jumper
and connects the VM-DACT, which provides a series connection to the telephones.
See the VM-DACT Dual Line Dialer Card Installation Sheet (P/N 3101786-EN) for a diagram of the jack
wiring.
• VM-DACT dialers can be used for most applications that use telephone lines. The exceptions are:
• The central station telephone number cannot be dialed directly (using access numbers and area code
where necessary) without operator interception of the call
• Multiparty service (a party line) exists
• Operator assistance is required to complete a telephone call and a foreign exchange cannot be
introduced
• Connection is not established within 38 seconds following completion of dialing
• The VM-DACT dialer circuit is compatible with any switched telephone network that employs direct dialing
(local) and Direct Distance Dialing (DDD), without operator interception of the call.
• Operator interception occurs in some areas where message billing is not completely automatic. Where
operator interception is involved, you must obtain a foreign exchange (FX) connection from the central station
exchange to the exchange serving the customer. The FX provides a local number for calling the central
station without toll billing. A WATS or ground-start line connection must not be used for this purpose because
the line cannot be supervised.
• The VM-DACT includes a feature that prevents jamming by an incoming telephone call. The feature is based
on a telephone service option referred to as called party disconnect. This option lets the receiver of a call
disconnect by hanging up the telephone for a period of time, even if the caller stays on the line. The time
required for disconnect varies in different areas, but is usually between 18 and 90 seconds. Called party
disconnect is available in most areas. To determine whether the called party disconnect control is available in
the area to be served, consult the local telephone company.
In areas not having called party disconnect, the VM-DACT module is vulnerable to jamming by an incoming
call. To minimize the possibility of jamming, we recommend that the customer order a separate, unlisted
number for exclusive use of the VM-DACT module. The customer should keep this number confidential. In the
case of the two-line dialer, two premises telephone numbers would have to be busied by incoming calls to jam
the system.
Progressive anti-jamming measures would entail the use of one unlisted telephone number, or two unlisted
numbers for maximum dialer integrity.
• The VM-DACT must be connected to the incoming line ahead of all connected equipment on that line, but just
behind the demarcation block. This puts the control unit telephone connection in series, assuring that all
telephones, answering machines, and FAX machines are disconnected during dial-out to the CMS. This
requirement is necessary so the VM-DACT dialer circuit can seize the line for its exclusive use in the event of
an alarm.
• Using a telephone line that is considered essential for conducting business at the site is not preferred. The
dialer must be the first connection in line because it seizes the line and disconnects all other equipment when
making a call. If connection will be made to a telephone company line that is also used for normal business
purposes, advise the customer that the telephone service will be disrupted for a few minutes during the
connection period.
• If the incoming lines to the protected premises involve a rotary telephone line arrangement, make the
connection to the line having the highest number. This will create the least interference with business lines.
• In areas where the telephone company requires their own connector block be installed, it should be wired as
per the USOC RJ-31X or RJ-38X configuration. (The RJ-38X configuration is identical to RJ-31X except for a
jumper between 2 and 7 that is used in some residential applications but is not used by the VM-DACT.)

Kidde VM-1 Specifications

General

Brand	Kidde
Model	VM-1
Category	Fire Alarms
Language	English