User Guide
2-6 Installation MN850
Figure 2-1 Power and Motor Circuit Connections
Programmable
Input
L1 L2 L3
Alternate *
Fuse
Connection
Note 1
L1 L2 L3
L1 L2 L3
* Circuit
Breaker
Earth
* Optional components not provided with control.
Note 4, 8
Baldor
Digital
Soft–Start
Note 1
Notes:
1. See “Protective Devices” described previously in this section.
2. Motor Overload and/or Thermal protection is required by NEC.
3. Use same gauge wire for Earth ground as is used for L1, L2
and L3.
4. Metal conduit should be used. Connect conduits so the use of
a Reactor or RC Device does not interrupt EMI/RFI shielding.
5. X1 and X2 control terminal power must be present or the logic
circuits will not work. Either 115VAC or 230VAC can be used.
Be sure the 115/230VAC switch (Control Voltage Selector
Switch) is set to the proper voltage before you apply power.
6. The X1 and X2 control voltage input has different VA ratings
depending on enclosure size, see Table 2-3.
7. Add appropriately rated protective device for AC relay
(snubber) or DC relay (diode).
8. To protect the control, be sure to add MOV protection. Refer to
Appendix D for additional information.
Note 3
See Recommended Tightening Torques in Table 2-4.
* AC Motor
T1 T2 T3
T1
T2 T3
G
14
11
K1
24
21
22
K2
S1
S0
115/230VAC
Note 5, 6
X1
X2
* Input
Contactor
IC
OT
or
OL
115/230VAC
K1 is factory preset
as the RUN" relay.
Note 2
Note 2
Motor Thermostat Leads
OT
*
115VAC
*
*
Note 6
Note 7
12
All soft–starters require a separate fused 2 wire, single phase connection at terminals X1
and X2. An external fuse is required and must be sized as described in Table 2-3.
Either 115VAC (98 – 126VAC) or 230VAC (196 – 253VAC) input may be used. The
control voltage selector switch allows simple selection of 115VAC or 230VAC input power.
Table 2-3 Control Supply
Chassis Size
Current Rating
(Amps)
Nominal Power Consumption
(VA)
115V Fuse 230V Fuse
to 23A 8VA 125mA 63mA
Size 1
30A to 44A 10VA 200mA 100mA
Size 1
59A to 146A 12VA 200mA 100mA
Size 2 174A to 370A 18VA 200mA 100mA
8VA – Control card 125mA 63mA
Size 3, 4 500A to 1200A
140VA – separate fan supply 2A 1A
Motor Overload and Thermal Protection
NEC and local codes may require thermal motor overload protection devices be installed
rather than rely only on internal protection devices. Devices such as bi–metallic overload
relays may require special Soft–Start settings (such as during low voltage starting to
prevent heating). Use of electronic overload relays with this control is not recommended
because of the distorted current waveform. A motor with built in thermal cutoff switches
(TSTAT’s) is recommended.