Control_Flippingbook_JULY 2026

NEMA FULL VOLTAGE POWER DEVICES, CONTROL SECTION 1

1-104

— Plug and play enclosed starters Product overview

Description • Across the line (D.O.L.) and 2-speed starters • Maximum UL/cUL horsepower ratings 5 HP to 100 HP max • NEMA size rated 00 to 4 • Maximum voltage 600 V AC • Non-combination and combination types available • Compact, space-saving design • Pre-wired pilot device and control transformer kits allow for quick and easy field modification and installation • Captive terminal screws • Touch safe design : All connection terminals are protected against accidental touch • External connections : all starters include necessary terminal blocks and wiring to control the starter by an external maintained contact when used with the appropriate pilot device kit

General information The extensive requirements for group motor circuits are : • Isolation and short-circuit protection • Motor control : Starting and stopping • Motor protection against overloads Those functions are presented in this section; the motor control and motor protection against overloads (See drawing below).

Enclosure types • Metal : Type 1, 4/12, 4X stainless steel type 304 # 4

Overload relay protection • All HP rated starters should use a class 10 adjustable overload relay • All NEMA rated starters should use a class 10/20/30 adjustable electronic overload relay • Generally, applications where NEMA-rated starters are required, customers would normally select the class 20 trip setting, however each application is different

The isolation and short-circuit protection can be provided by disconnect switches : OS/OT range or by Tmax® XT circuit breakers. Use the recommended fuses. For detailed information, please refer to coordination tables available on request. The control is provided by the contactor of the starter and the protection against overloads by the associated overload relay. As the supply circuit is normally rated for the motor full load current (FLC), the O/L relay protects both motor and supply circuit against overloads. High starting torque, simple and low-price direct motor starting with full voltage (so-called “direct-on-line” or D.O.L.) is the most common way of starting a motor. Starting torque and current depend on the motor type. Starting torque is roughly equal to 1.9 to 2.1 times the motor’s full speed value and starting current 5.5 to 7 times the motor FLC value. Quick to reach the full speed due to its high starting torque, the D.O.L. starter requires a strong power supply to handle this high inrush current.