Isolating Transformers | McMaster-Carr

	Input Voltage Input Voltage

	Power Output Power Output

	Output Voltage Output Voltage

	Transformer Voltage Function Transformer Voltage Function

Constant

Step Down

Step Up

	Electrical Phase Electrical Phase

Single

Three

	Frequency Frequency

50Hz

60Hz

	Input Connection Type Input Connection Type

Hardwire

Plug

	Environment Environment

Corrosive

Damp

Outdoor

	Width Width

	Height Height

	Specifications Met Specifications Met

CSA

	Output Connection Type Output Connection Type

Hardwire

Socket

	Input Wire Connection Type Input Wire Connection Type

Wire Leads

Screw Terminals

Bus Bar

	Depth Depth

	Output Wire Connection Type Output Wire Connection Type

Wire Leads

Screw Terminals

Bus Bar

	DFARS (Defense Acquisition Regulations Supplement) DFARS (Defense Acquisition Regulations Supplement)

DFARS Specialty Metals
COTS-Exempt

	REACH (Registration, Evaluation, Authorization and Restriction of Chemicals) REACH (Registration, Evaluation, Authorization and Restriction of Chemicals)

REACH Compliant

	Input Connection NEMA Style Input Connection NEMA Style

5-15

6-15

	RoHS (Restriction of Hazardous Substances) RoHS (Restriction of Hazardous Substances)

RoHS Compliant

Forward

How can we improve?

35 Products

About AC to AC Voltage Transformers

For single-phase equipment, use this formula to find power output: VA = Volts × Amps

For three-phase equipment, use this formula to find power output: VA = Volts × Amps × 1.73

Single Phase with Plug and Socket

Single Phase

Three Phase

These transformers have isolated primary and secondary coils to protect your sensitive equipment from input voltage spikes.

Three phase transformers have Wye wiring for output voltage.

Sealed coils and cores prevent corrosion and insulation damage.

When wired as constant voltage transformers, they filter out voltage spikes and electrical noise.

Transformers that cannot be sold to California are restricted by local energy efficiency regulations.

Single Phase—Plug Input and Socket Output

NEMA 5-15 Plug

NEMA 5-15 Socket

NEMA 6-15 Plug

Voltage
Input	Output	Power Output, VA	Input Plug Type (NEMA Style)	Output Socket Type (NEMA Style)	Ht.	Wd.	Dp.	Features		Each
Constant Voltage
115V AC	115V AC	150	Three Prong (5-15)	Three Slot (5-15)	3.9"	3.1"	4.2"	Isolated Coils	00000000	0000000
115V AC	115V AC	250	Three Prong (5-15)	Three Slot (5-15)	4.7"	3.8"	4.4"	Isolated Coils	00000000	000000
115V AC	115V AC	500	Three Prong (5-15)	Three Slot (5-15)	4.7"	3.8"	6"	Isolated Coils	00000000	000000
115V AC	115V AC	1,000	Three Prong (5-15)	Three Slot (5-15)	5.4"	4.4"	8.1"	Isolated Coils	00000000	000000
Step Down Voltage
230V AC	115V AC	100	Three Prong (6-15)	Three Slot (5-15)	3 1/2"	2.8"	3.6"	Isolated Coils	00000000	000000
230V AC	115V AC	250	Three Prong (6-15)	Three Slot (5-15)	4.7"	3.8"	4.4"	Isolated Coils	00000000	000000
230V AC	115V AC	500	Three Prong (6-15)	Three Slot (5-15)	4.7"	3.8"	6"	Isolated Coils	00000000	000000
230V AC	115V AC	1,000	Three Prong (6-15)	Three Slot (5-15)	5.4"	4.4"	8.1"	Isolated Coils	00000000	000000

Single Phase—Wire Leads Input and Output

Voltage
Input	Output	Power Output, VA	Ht.	Wd.	Dp.	Features	Environment	Environmental Rating	Specifications Met		Each
Step Up/Step Down/Constant Voltage
120V AC, 240V AC	120V AC, 240V AC	1,000	10 1/2"	5 1/2"	5.1"	Isolated Coils, Sealed Coils, Sealed Cores	Outdoor	NEMA 3R	UL Listed, C-UL Listed	0000000	0000000
120V AC, 240V AC	120V AC, 240V AC	2,000	13"	5 1/2"	5.1"	Isolated Coils, Sealed Coils, Sealed Cores	Outdoor	NEMA 3R	UL Listed, C-UL Listed	0000000	000000
120V AC, 240V AC	120V AC, 240V AC	3,000	11 1/2"	10.3"	7.1"	Isolated Coils, Sealed Coils, Sealed Cores	Outdoor	NEMA 3R	UL Listed, C-UL Listed	0000000	000000
120V AC, 240V AC	120V AC, 240V AC	5,000	14.4"	10.3"	7.1"	Isolated Coils, Sealed Coils, Sealed Cores	Outdoor	NEMA 3R	UL Listed, C-UL Listed	0000000	00000000
Step Down/Constant Voltage
240V AC, 480V AC	120V AC, 240V AC	750	11.3"	5.3"	6 1/2"	Isolated Coils, Sealed Coils, Sealed Cores	Outdoor	NEMA 3R	UL Listed, C-UL Listed	0000000	000000
240V AC, 480V AC	120V AC, 240V AC	1,000	11.3"	5.3"	6 1/2"	Isolated Coils, Sealed Coils, Sealed Cores	Outdoor	NEMA 3R	UL Listed, C-UL Listed	0000000	000000
240V AC, 480V AC	120V AC, 240V AC	1,500	13.3"	6.3"	7.8"	Isolated Coils, Sealed Coils, Sealed Cores	Outdoor	NEMA 3R	UL Listed, C-UL Listed	0000000	000000
240V AC, 480V AC	120V AC, 240V AC	3,000	13.3"	6.3"	7.8"	Isolated Coils, Sealed Coils, Sealed Cores	Outdoor	NEMA 3R	UL Listed, C-UL Listed	0000000	000000
240V AC, 480V AC	120V AC, 240V AC	5,000	15"	10.2"	10.6"	Isolated Coils, Sealed Coils, Sealed Cores	Outdoor	NEMA 3R	UL Listed, C-UL Listed	0000000	000000
240V AC, 480V AC	120V AC, 240V AC	7,500	15.2"	13 1/2"	10.8"	Isolated Coils, Sealed Coils, Sealed Cores	Outdoor	NEMA 3R	UL Listed, CSA Certified	0000000	00000000
240V AC, 480V AC	120V AC, 240V AC	10,000	15.2"	13 1/2"	10.8"	Isolated Coils, Sealed Coils, Sealed Cores	Outdoor	NEMA 3R	UL Listed, CSA Certified	0000000	00000000
240V AC, 480V AC	120V AC, 240V AC	15,000	16.9"	14.1"	11.6"	Isolated Coils, Sealed Coils, Sealed Cores	Outdoor	NEMA 3R	UL Listed, CSA Certified	0000000	00000000
240V AC, 480V AC	120V AC, 240V AC	25,000	18.4"	16.1"	13.3"	Isolated Coils, Sealed Coils, Sealed Cores	Outdoor	NEMA 3R	UL Listed, CSA Certified	0000000	00000000

Three Phase—Wire Leads Input and Output

Voltage
Input	Output	Power Output, VA	Ht.	Wd.	Dp.	Features	Environment	Environmental Rating	Specifications Met		Each
Step Down Voltage
480V AC	120V AC, 208V AC	3,000	10.4"	12.4"	7 1/2"	Isolated Coils, Sealed Coils, Sealed Cores	Outdoor	NEMA 3R	UL Listed, CSA Certified	0000000	000000000
480V AC	120V AC, 208V AC	6,000	11.8"	14.2"	8.8"	Isolated Coils, Sealed Coils, Sealed Cores	Outdoor	NEMA 3R	UL Listed, CSA Certified	0000000	00000000
480V AC	120V AC, 208V AC	9,000	14"	17.8"	11 1/2"	Isolated Coils, Sealed Coils, Sealed Cores	Outdoor	NEMA 3R	UL Listed, CSA Certified	0000000	00000000
480V AC	120V AC, 208V AC	15,000	18.9"	20.3"	9"	Isolated Coils, Sealed Coils, Sealed Cores	Outdoor	NEMA 3R	UL Listed, CSA Certified	0000000	00000000

Three Phase—Bus Bar Input and Output

Voltage
Input	Output	Power Output, VA	Ht.	Wd.	Dp.	Features	Environment	Environmental Rating	Specifications Met	Cannot Be Sold To		Each
Step Down Voltage
480V AC	120V AC, 208V AC	30,000	25 1/2"	24.4"	19.4"	Isolated Coils, Sealed Coils, Sealed Cores	Outdoor	NEMA 3R	UL Listed, CSA Certified	CA	0000000	000000000
480V AC	120V AC, 208V AC	45,000	25 1/2"	24.4"	19.4"	Isolated Coils, Sealed Coils, Sealed Cores	Outdoor	NEMA 3R	UL Listed, CSA Certified	CA	0000000	00000000
480V AC	120V AC, 208V AC	75,000	29.4"	28.2"	22.4"	Isolated Coils, Sealed Coils, Sealed Cores	Outdoor	NEMA 3R	UL Listed, CSA Certified	CA	0000000	00000000

Enclosed Voltage-Stabilizing AC to AC Transformers

Protect sensitive equipment from electromagnetic interference and maintain power during three-millisecond power dips. These transformers also isolate output and input voltage (output regulation is ±3% with input voltage fluctuations from +10% to -20%). When wired for constant voltage, transformers filter out voltage spikes and electrical noise.

Voltage
Input	Output	Power Output, VA	Ht.	Wd.	Dp.	Specifications Met		Each
Single Phase—Screw Terminals Input and Output
Step Up/Step Down/Constant Voltage
120V AC, 208V AC, 240V AC, 480V AC	120V AC, 208V AC, 240V AC	140	4.4"	6"	8 1/2"	UL Listed, CSA Certified	0000000	0000000
120V AC, 208V AC, 240V AC, 480V AC	120V AC, 208V AC, 240V AC	250	4.4"	6"	9.7"	UL Listed, CSA Certified	0000000	000000
120V AC, 208V AC, 240V AC, 480V AC	120V AC, 208V AC, 240V AC	500	6 1/2"	6.3"	12.3"	UL Listed, CSA Certified	0000000	000000
120V AC, 208V AC, 240V AC, 480V AC	120V AC, 208V AC, 240V AC	750	6 1/2"	6.3"	13.3"	UL Listed, CSA Certified	0000000	00000000
120V AC, 208V AC, 240V AC, 480V AC	120V AC, 208V AC, 240V AC	1,000	6 1/2"	6.3"	14.2"	UL Listed, CSA Certified	0000000	00000000
120V AC, 208V AC, 240V AC, 480V AC	120V AC, 208V AC, 240V AC	1,500	9.9"	9.4"	17.6"	UL Listed, CSA Certified	0000000	00000000
120V AC, 208V AC, 240V AC, 480V AC	120V AC, 208V AC, 240V AC	3,000	9.9"	9.4"	19.9"	UL Listed, CSA Certified	0000000	00000000

Email Us

About AC to AC Voltage Transformers

Enclosed Isolating AC to AC Transformers

Enclosed Voltage-Stabilizing AC to AC Transformers