Carrier 23XL Specifiche Scaricare il pdf (Pagina 12)

These starters operate by reducing the starting voltage. The

starting torque of a motor at full voltage is typically 125%

to 175% of the running torque. When the voltage and the

current are reduced at start-up, the starting torque is reduced

as well. The objective is to reduce the starting voltage to just

the voltage necessary to develop the torque required to get

the motor moving. The voltage and current are then ramped

up in the desired period of time. The voltage is reduced through

the use of silicon controlled rectiﬁers (SCR). Once full volt-

age is reached, a bypass contactor is energized to bypass the

SCRs.

When voltage is supplied to the solid-state circuitry, the

heat sinks within the starter are at line voltage. Do not

touch heat sinks while voltage is present or serious in-

jury will result.

There are a number of LEDs (light-emitting diodes) that

are useful in troubleshooting and starter check-out on

the Benshaw, Inc. solid-state starters. These are used to

indicate:

• voltage to the SCRs

• SCR control voltage

• power indication

• proper phasing for rotation

• start circuit energized

• overtemperature

• ground fault

• current unbalance

• run state

These LEDs (on Benshaw, Inc. solid-state starters) are fur-

ther explained in the Check Starter and Troubleshooting Guide

sections, pages 49 and 68.

Unit Mounted Wye-Delta Starter (Optional) —

The 23XL machine may be equipped with a wye-delta starter

mounted on the unit. This starter is intended for use with

low-voltage motors (under 600 v). It reduces the starting cur-

rent inrush by connecting each phase of the motor windings

into a wye conﬁguration. This occurs during the starting pe-

riod when the motor is accelerating up to speed. After a time

delay, once the motor is up to speed, the starter automati-

cally connects the phase windings into a delta conﬁguration.

1—Pilot Relays (PR1 to PR5)

2—Circuit Breaker 4

3—Silicon Controlled Rectiﬁer (SCR) (One of 6) (Hidden)

4—Circuit Breaker 3

5—Solid-State Controller

6—Circuit Breaker 2

7—Circuit Breaker 1

8—Ammeter (Optional)

9—Voltmeter (Optional)

10 — Overload Calibration Unit

11 — Field Wiring Terminal Strips (TB2 and TB3) (Hidden)

12 — Starter Management Module (SMM)

13 — Starter Access Door

Fig. 8A — Cutler-HammerT Solid-State Starter,

Internal View

1—Field Wiring Terminal Strips (TB2 and TB3)

2—Circuit Breakers 1, 2, 3, 4

3—Overload Calibration Unit

4—Solid-State Controller

5—SCR LED (One of 6)

6—Starter Fault and Run LEDs

7—Voltmeter (Optional)

8—Ammeter (Optional)

9—Silicon Controlled Rectiﬁer

(SCR) (One of 6)

10 — Voltage LED

11 — Starter Management Module (SMM)

12 — Pilot Relays (PR1 to PR6)

13 — Starter Access Door

Fig. 8B — Benshaw, Inc. Solid-State Starter,

Internal View

Fig.9—Typical Solid-State Starter, Front View

1 2 ... 7 8 9 10 11 12 13 14 15 16 17 ... 103 104

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