Technical data

Chapter 4: Installation
Series SPB Audio Boosters Manual, Revision A
4-15
Table 4-1. Series SPB Wiring Modes
Wiring Mode When To Use Effects Section
Two-Wire Mode with
AC Loss reported on
Main Trouble
Contacts
This mode is
generally used
when no secondary
operations (BGM,
Telephone Paging,
etc.) are being used
on the SP40S and
the least amount of
connection wires is
desirable.
If one Audio
Booster has any
trouble, then all
Audio Boosters
connected to the
SP40S lose
secondary
operations.
4.2.1.
Four-Wire Mode with
AC Loss reported on
Main Trouble
Contacts
This mode is
generally used
when secondary
operations (BGM,
Telephone Paging,
etc.) are being used
on the SP40S.
If one Audio
Booster has any
trouble, only that
Audio Booster
loses secondary
operations.
4.2.2.
*Two-Wire Mode with
AC Loss reported on
AC TRB Contacts
This mode is
generally used
when no secondary
operations (BGM,
Telephone Paging,
etc.) is being used
on the SP40S.
If one Audio
Booster has an
AC Loss trouble,
then all Audio
Boosters
connected to the
SP40S lose
secondary
operations.
4.2.3.
*Four-Wire Mode with
AC Loss reported on
AC TRB Contacts
This mode is
generally used
when secondary
operations (BGM,
Telephone Paging,
etc.) are being used
on the SP40S.
If one Audio
Booster has an
AC Loss trouble,
only that Audio
Booster loses
secondary
operations.
4.2.4.
* Note: One of these modes may be required by Underwriters Laboratories when system troubles
need to be transmitted to an off-site location.