2.3.2 Installing the Option Electrical Connections
Setpoint
electrical
connection
Cable assembly
The setpoint board is connected through a 25-pin, male, sub-miniature
D connector. The mating connector is supplied with the option, but is
not wired due to the large variety of installation configurations that are
possible. For each setpoint, there are three connections:
• NC (normally closed)
• C (common)
• NO (normally open)
When the setpoint is off, NC is switched to C. When the setpoint turns
on, C is switched to NO and NC is open. The maximum current is 1 A,
and the voltage should not exceed 28V. The following table lists the
electrical connections to the setpoint board.
Table 2-1. Setpoint Option Electrical Connections
Pin
Function
2
SPl NC
9
SPl C
1
SPl NO
4
SP2NC
11
SP2 C
,.,
SP2NO
.)
8
SP4 NC (fail-safe)
15
SP4C
7
SP4NO
23
STBY
10
OPER
22
CTL RETURN
STBY, OPER, and CTL RETURN lines remotely control the
DIGITEL to the standby and operate modes. A +12 to +28V signal is
placed between STBY and CTRL RETURN as appropriate.
A shielded cable should be used when connecting to the DIGITEL.
All pre-assembled cables provided by PHI are shielded. The cable
should be assembled as follows:
1. Strip back the outer insulation of the cable to 1.5 in. (38 mm),
exposing the shield.
2. Strip the shield back to 1/4 in. (6 mm) of the outer insulation.
2-10
Installation
