MA-792 Installation and Operating Instructions
4
MA-792 TERMINAL DESCRIPTIONS
The following is a description for each of the field terminals, along with expected voltage readings
under specified conditions. Voltages are read with a 20,000 OHMS/Volt DC, 10,000 OHMS/Volt
AC meter,with reference to terminal T2, except where noted otherwise:
T1 16 VAC power input for amplifier and control circuits, this terminal must be positive when
powering with DC.
T2 Power Supply common & 0 volt reference.
T3 Door strike transformer input.
L1 Positive output terminal for door strike.
L2 Negative output terminal for door strike.
L3, L4 AC output for door strike: output voltage across L3, L4 is identical to input between T3, T2
when door strike is activated.
P Postal lock door control input, carries approximately +11 VDC when not in use, door strike
is activated by shorting terminal P to G.
A Door strike control output, used for multiple-entrance systems, normally at 0 Vdc, +12Vdc
when door circuit is activated.
S1 Output for 45 Ohm entry panel loudspeaker, carries 0-5 VAC voice signals when
operating.
S2 Return path for signal on terminal S1, internally connected to common terminal T2.
R Output for optional handset receiver on entry panel, carries ~0.5 Vac voice signals when
operating.
M1 Microphone input, for use with entry panel microphone, signal from microphone is 0-2 mV
AC.
M2 Return path for microphone signal on terminal M1, internally connected to terminal T2.
1 Suite station receiver line, carries 0 ~ 1 VAC voice signals when in operation.
2 Suite station microphone line, carries +12 VDC when all handsets are on their bases, ~ +6
VDC when one handset is lifted.
6 Return for audio paths of terminals 1 & 2, internally connected to terminal T2.
9 Door control input from suite stations, normally at +11 Vdc, 0 Volts when door button on
suite station is depressed.
Z Call tone generator output, normally at +22 Vdc, supplies ~ 10 Vac call tone signal when a
call button is depressed.
