Sed2 Vfd Nema Type 3R/3Rhe Bypass Overview - Siemens SED2 VFD NEMA Operating Instructions Manual

SED2 VFD NEMA Type 3R/3RHE Bypass Operating Instructions
SED2 VFD NEMA Type 3R/3RHE Bypass
Overview
During normal operation of a NEMA Type 3R/3RHE Bypass in a typical application, the input
and output contactors close and the SED2 operates the motor (Figure 1). The bypass
contactor provides the ability to operate the motor on utility power and eliminate the SED2
from the motor control circuit.
The NEMA Type 3R/3RHE bypass consists of a SED2, NEMA Type 3R/3RHE bypass
enclosure, and controls. NEMA Type 3R/3RHE bypass components (Figure 2 and 4) include:
•
Control terminal block
•
"Drive-Off-Bypass" switch
•
"Bypass On" light
•
"Drive Test On-Off" switch (optional)
•
Control Transformer
•
Power fuses
•
Relays
4
Motor
2 Contactor Bypass
Figure 1. Functional Diagram of Typical NEMA Type 3R/3RHE Bypass.
Input
Device
Drive Drive
Motor
3 Contactor Bypass
•
Overload (current) relay
•
Bypass Contactor
•
Output Contactor
•
Input Contactor (optional on the Type
NEMA 3R, standard on Type 3RHE)
•
Motor Contactor
•
Disconnect switch
•
Heater
Input
Device
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