Telex MCE325 - Manual (Page 28)

2-8 C S I - 2 0 0 U s e r I n s t r u c t i o n s
Electrical Installation
AC Power and Fuse
The Model MCE325 is pre-wired for either 115 or 230 VAC operation, and the appropriate fuse is
already installed. The MCE325 uses a 0.5A Slo-Blo fuse for 115 volt operation, or a 0.25A Slo-
Blo fuse for 230 volt operation. (A fused external DC source may be used instead of AC power if
desired. (See “External DC Power Source”.)
Intercom Lines J8, J9, and J10
General
Intercom line connectors J8 and J9 are parallel-wired for loop-through connection to other
intercom stations. These connectors are used for connection of two-wire lines to channels one and
two (full-duplex operation), or for connection of four-wire channel A output (channel A input is
connected at the auxiliary connector).
Intercom line connector J10 is used for connection of two-wire lines to channels three and four
(full-duplex operation), or for connection of four-wire channel B output (channel B input is
connected at the auxiliary connector).
Connector Pin-outs
Four-wire Output Termination
Figure 2.4 4-wire output terminations.
When four-wire outputs are used, termination resistors must be installed for proper operation. The
output amplifiers are current sources, and the output level is determined by the terminating
Table 2.4 Connectors J8 and J9.
PIN # FUNCTION
1 Common (low side of line)
2 Two-wire CH 1 or four-wire CH A high output
3 Two-wire CH 2 or four-wire CH A low output
Table 2.5 Connection J10
PIN # FUNCTION
1 Common (low side of line)
2 Two-wire CH 3 or four-wire CH B high output
3 Two-wire CH 4 or four-wire CH B low output