GE 889 - Wire Size; Phase Sequence and Transformer Polarity

2–20 889 GENERATOR PROTECTION SYSTEM – INSTRUCTION MANUAL
ELECTRICAL INSTALLATION CHAPTER 2: INSTALLATION
Table 2-7: DCmA I/O
Wire Size Use the following guideline when selecting wires or lugs to connect to terminal strips A, B,
C, D, E, F, G, H, and terminal blocks J, K. Note that the first two bullets are applicable to
terminal blocks J and K only:
• 12 AWG to 22 AWG (3.3 mm
2
to 0.3 mm
2
): Single wire termination with/without 9.53
mm (0.375”) maximum diameter ring terminals.
• 14 AWG to 22 AWG (2.1 mm
2
to 0.3 mm
2
): Multiple wire termination with 9.53 mm
(0.375”) maximum diameter ring terminals. Two ring terminals maximum per circuit.
• Suggested wiring screw tightening torques are: terminal strips A-H tighten to 4.5 in-lbs
(0.5 N-m) and terminal blocks J, K to 15 in-lb (1.7 N-m).
Figure 2-20: Fiber Connector Types (S - ST)
Phase Sequence and Transformer Polarity
For correct operation of the relay features, follow the instrument transformer polarities,
shown in the Typical Wiring Diagram above. Note the solid square markings that are
shown with all instrument transformer connections. When the connections adhere to the
drawing, the arrow shows the direction of power flow for positive watts and the positive
direction of lagging vars. The phase sequence is user programmable for either ABC or ACB
rotation.
The 889 relay has four (4) current inputs in each J slot and K slot. Three of them are used
for connecting to the phase CT phases A, B, and C. The fourth input is a ground input that
can be connected to either a ground CT placed on the neutral from a Wye connected
transformer winding, or to a “donut” type CT measuring feeder ground fault current.
889
relay CT inputs are grouped into terminal block assembly, mounted on the rear of the
chassis. There are no internal ground connections on the current inputs. Current
transformers with 1 to 12000
A primaries may be used.
CAUTION:
Verify that the relay’s nominal input current of 1 A or 5 A matches the secondary rating
of the connected CTs. Unmatched CTs may result in equipment damage or inadequate
protection.
Analog Output Analog Input
Terminal Description Terminal Description
1 + (Real Power) 10 + (1)
2 + (Apparent Power) 11 + (2)
3 + (Reactive Power) 12 + (3)
4 + (Power Factor) 13 + (4)
5 + (Load Current) 14 RETURN
6 + (Unbalance Current) 15 SHIELD
7 + (Line Voltage)
8 RETURN
9 SHIELD