Voltage Inputs; Digital Inputs - GE 469 Manual

2 INSTALLATION 2.2 ELECTRICAL

2.2.7 VOLTAGE INPUTS

The 469 has three channels for AC voltage inputs, each with an isolating transformer. There are no internal
fuses or ground connections on the voltage inputs. The maximum VT ratio is 150.00:1. The two VT connec-
tions are open delta (see Figure 2–10: TYPICAL WIRING DIAGRAM on page 2–8) or wye (see below). The
voltage channels are connected in wye internally, which means that the jumper shown on the delta-source con-
nection of the TYPICAL WIRING DIAGRAM, between the phase B input and the 469 neutral terminal, must be
2
installed for open delta VTs.
Polarity of the VTs is critical for correct power measurement and voltage phase reversal operation.
A 1 A fuse is typically used to protect the inputs.
Figure 2–16: WYE VOLTAGE TRANSFORMER CONNECTION

2.2.8 DIGITAL INPUTS

There are 9 digital inputs designed for dry contact connections only. Two of the digital inputs (Access and Test)
have their own common terminal; the balance of the digital inputs share one common terminal (see Figure 2–
10: TYPICAL WIRING DIAGRAM on page 2–8).
In addition, the +24 V DC switch supply is brought out for control power of an inductive or capacitive proximity
probe. The NPN transistor output could be taken to one of the assignable digital inputs configured as a counter
or tachometer. Refer to Section 1.2: SPECIFICATIONS on page 1–5 for maximum current draw from the
+24 V DC switch supply.
DO NOT INJECT VOLTAGES TO DIGITAL INPUTS. DRY CONTACT CONNECTIONS ONLY.
CAUTION
GE Power Management 469 Motor Management Relay 2-13