Technical data
    Chapter 4: Installation   
Series SPB Audio Boosters Manual, Revision A 
4-5
Table 4-2. Terminal Blocks Connection Definitions 
Symbol  Full Name  Definition 
TB1 
AC IN  AC sensing Input Connection 
Factory connection senses proper AC Voltage input. Low AC or no AC input 
will light the AC LED and cause a trouble condition. 
STB IN  Strobe Input (SPB-80/4 Only) 
Power limited 8 to 33VDC (10mA) NAC power limited source or contact 
closure input. Initiates Strobe Outputs on the SPB-80/4 only 
TB2 
STB RET  Strobe Return (SPB-80/4 Only) 
Strobe Input Return - Used to continue strobe input circuit, connecting 
additional strobe input circuits from audio boosters, Strobe appliances or 
voice evacuation panel’s 1/2W EOLR. 
DC IN  DC Input 
Factory wired 24VDC Input from power supply (SPBPS) 
TB3 
BATTERY  Battery 
24VDC Battery connection for battery charging and battery backup. 
TB4 
AC TRB 
AC Trouble Reporting 
Provides AC loss trouble when reporting to off-site location. 
AUD2 OUT  Audio 2 Output (SPB-160 Only) 
Audio Output #2 - Provides 25V or 70.7V, power limited audio output at 80 
watts. Supervised using a UL Listed 10K Ohm 1/2W EOLR. 
AUD1 OUT  Audio 1 Output 
Audio Output #1 - Provides 25V or 70.7V power limited audio output at 80 
watts. Supervised using a UL Listed 10K Ohm 1/2W EOLR. 
STB2 OUT  Strobe 2 Output (SPB-80/4 
Only) 
Regulated 27VDC at 2.0A NAC power limited Supervised using a UL Listed 
10K Ohm 1/2W EOLR. 
TB5 
STB1 OUT  Strobe 1 Output (SPB-80/4 
Only) 
Regulated 27VDC at 2.0A NAC power limited Supervised using a UL Listed 
10K Ohm 1/2W EOLR. 
AUDIO IN  Audio Input 
1V, 25V, or 70.7V power limited audio input. Blocking capacitor for DC 
Supervision. Power consumption is 1.2 Watts @ 70.7V and 0.25 Watts @ 
25V. 
AUDIO RET  Audio Return 
Audio Input Return. Used to continue Audio Circuit from the voice 
evacuation panel, connecting additional audio boosters, or voice evacuation 
panel’s 1/2W EOLR. 
AUX IN  Auxiliary Input 
8 to 33VDC (10mA) NAC power limited source or contact closure input. 
Used in the Four Wire mode. Applying an alarm input restores audio booster 
to full power from the power saver mode when panel is in battery backup 
mode. 
TB6 
AUX RET  Auxiliary Return 
8-33VDC (10mA) NAC power limited source (only) Auxiliary input return. 
Used to connect to additional audio boosters through the voice evacuation 
panel. 
EXP OUT  Expansion Out 
27VDC at 0.5A power limited circuit energized when a signal is applied to 
AUX IN or Strobe In. Reverse polarity Supervised using a UL Listed 10K 
Ohm 1/2W 1/2W EOLR. 
TB7 
DC OUT  DC Output 
27VDC at 0.5A, non-power limited used for splitter power only. 
TB8 
TRB 
Trouble Reporting 
Provides trouble reporting when not connected to SP40S. 










