Schweitzer Engineering Laboratories SEL-351 - Current Transformer Inputs; High-Current Interrupting Output Contacts; Models 0351 Xt and 0351 Xy; Optoisolated Inputs

2-12 Installation Date Code 20001006
SEL-351 Instruction Manual
High-Current Interrupting Output Contacts
Models 0351x1 and 0351xY part numbers with a numeral “6” in the field underlined below
(sample part numbers) indicate high-current interrupting output contacts on the extra I/O board
(OUT201 through OUT212):
0351x1H42546X1 0351xYH42546X1
High-current interrupting output contacts are polarity dependent. Note the “+” polarity markings
above even-numbered terminals B02, B04, B06, ..., B24 in Figure 2.5. The extra I/O board of the
Model 0351x1 relay in Figure 2.4 does not show these “+” polarity markings (because it is the rear
panel for an extra I/O board with standard output contacts).
As an example, consider the connection of terminals B01 and B02 (high-current interrupting
output contact OUT201) in a circuit:
Terminal B02 (+) has to be at a higher voltage potential than terminal B01 in the circuit.
The same holds true for output contacts OUT202 through OUT212 (if they are also high-
current interrupting output contacts).
Note: Do not use the high-current interrupting output contacts to switch ac control signals.
Optoisolated Inputs
The optoisolated inputs in any of the SEL-351 Relay models (e.g., IN5, IN102, IN207) are not
polarity dependent. With nominal control voltage applied, each optoisolated input draws
approximately 4 mA of current. Refer to General Specifications in Section 1: Introduction and
Specifications for optoisolated input ratings.
Refer to the serial number sticker on the relay rear panel for the optoisolated input voltage rating
(listed under label: LOGIC INPUT).
Current Transformer Inputs
Models 0351xT and 0351xY
The wiring harness includes a prewired 8-position ct shorting connector. Note the polarity dots
above terminals Z01, Z03, Z05, and Z07. Refer to Figure 2.7 through Figure 2.14 for typical ct
wiring examples.
Plug the ct shorting connector into terminals Z01 through Z08. Secure the connector to the relay
chassis with the two screws located on either end of the connector. When removing the ct shorting
connector, pull it straight out away from the rear panel. With the ct shorting connector removed
from the rear panel, internal mechanisms in the connector separately short out each individual
power system current transformer.
The connector accepts wire size AWG 16 to 10. A special tool is used to attach the wire to the
connector at the factory.
Courtesy of NationalSwitchgear.com