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CHAPTER 4: PROGRAMMING
4.7
Multi-speed Motor
OPTION
OPTION SWITCH 1 FUNCTION
SWITCH 1
STATUS
X
ALTERNATE SETPOINTS
OPEN
ALTERNATE SETPOINTS
CLOSED
ALTERNATE SETPOINTS
X
ALTERNATE SETPOINTS
X
ALTERNATE SETPOINTS
OPEN
ALTERNATE SETPOINTS
CLOSED
ALTERNATE SETPOINTS
OPEN
ALTERNATE SETPOINTS
CLOSED
ALTERNATE SETPOINTS
X = don't care
MAIN = main setpoints
239 MOTOR PROTECTION RELAY – INSTRUCTION MANUAL
Courtesy of NationalSwitchgear.com
The 239 has a multi-speed motor feature. This feature is intended to provide proper
protection for a two, three, or four-speed motor where there will be different full motor
characteristics (based upon speed settings). The algorithm integrates the heating at each
speed into one thermal model using a common, thermal capacity used register for all
speeds.
If the two-speed motor feature is used, OPTION SWITCH 1 and/or OPTION SWITCH 2 will be
dedicated as the two-speed motor. Terminals 41 and 46 (and/or 42 and 47) will be
monitored for a contact closure – closure of the contact will signify that the motor is in
Speed 2. If the input is open, it signifies that the motor is in Speed 1. This allows the 239 to
determine which setpoints should be active at any given point in time.
•
OPTION SWITCH 1-2 ALTERNATE SETPOINTS: The alternate setpoints only appear if
the
OPTION SWITCH FUNCTION
below, there are six alternate setpoints that are divided into 3 sets. The following table
shows the conditions required to select the appropriate set of alternate setpoints.
Table 4–4: Selecting Alternate Setpoints
OPTION
SWITCH 2
STATUS
anything but
anything but
OPEN
anything but
CLOSED
OPEN
OPEN
CLOSED
CLOSED
The message shown below is available on the 239, to indicate which is the currently
selected group. The 239 will also indicate the setpoints group that was in use at the
time of the last trip.
xxxx SETPOINTS GROUP
CURRENTLY IN USE
Located in ACTUAL VALUES pages A1 under
the sub-heading SWITCH STATUS
is set to
ALTERNATE SETPOINTS
OPTION SWITCH 2 FUNCTION
anything but
X
ALTERNATE SETPOINTS
anything but
X
ALTERNATE SETPOINTS
anything but
X
ALTERNATE SETPOINTS
ALTERNATE SETPOINTS
ALTERNATE SETPOINTS
ALTERNATE SETPOINTS
ALTERNATE SETPOINTS
ALTERNATE SETPOINTS
ALTERNATE SETPOINTS
xxxx = MAIN, 2nd, 3rd, 4th
. As shown in the table
SELECTED
SETPOINTS SET
MAIN
MAIN
nd
2
MAIN
rd
3
MAIN
nd
2
rd
3
th
4
4–47
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