The Siemens 3TF44 is a 3-pole World Series motor contactor, and its BRAH Electric replacement is the B3TF44: the Siemens number with a B added in front. BRAH lists six versions with 24VAC, 110/120VAC, 240VAC and 480VAC coils, each with a catalogue rating of 32A and 25HP at 600V and 2 NO / 2 NC auxiliary contacts. If the body of the contactor is still sound, the coil, the main contacts, the auxiliary block and the 3UA overload relay are listed as separate parts, so a full replacement is one option of several.
This page covers the 3TF44 alone. For every other size from 3TF30 to 3TF57, see the Siemens 3TF replacement guide for the whole range.
3TF44 replacement options at a glance
- Replace the contactor. Order the B3TF44 listing whose coil voltage matches the control circuit. The suffix after the dash on the Siemens number carries over unchanged.
- Replace the coil. The 3TY7443 coils fit the 3TF44 and are listed in six voltages from 24VAC to 480VAC.
- Replace the contacts. The B3TY7440-0A contact kit is listed for the 3TF44.
- Replace the overload relay. Four 3UA series are listed for this contactor: 3UA52, 3UA54, 3UA55 and 3UA59.
- Everything here is under replacement contactors, magnetic coils, contact kits and overload relays on the site.
3TF44 part numbers and their BRAH replacements
The first column is the number as printed on the Siemens nameplate. The last column gives the separate 3TY7443 coil with the same suffix, for use when only the coil needs changing.
| Siemens number | BRAH replacement | Coil voltage | Amperage (catalogue) | Horsepower (catalogue) | Auxiliary contacts | Separate coil with the same suffix |
|---|---|---|---|---|---|---|
| 3TF44 | B3TF44 | 110/120VAC | 32A | 25HP | 2 NO / 2 NC | Read the code on the installed coil |
| 3TF4422 | B3TF4422 | 110/120VAC | 32A | 25HP | 2 NO / 2 NC | Read the code on the installed coil |
| 3TF4422-0AC2 | B3TF4422-0AC2 | 24VAC | 32A | 25HP | 2 NO / 2 NC | B3TY7443-0AC2 (24VAC, 50/60Hz) |
| 3TF4422-0AK6 | B3TF4422-0AK6 | 110/120VAC | 32A | 25HP | 2 NO / 2 NC | B3TY7443-0AK6 (120VAC, 60Hz) |
| 3TF4422-0AP6 | B3TF4422-0AP6 | 240VAC | 32A | 25HP | 2 NO / 2 NC | B3TY7443-0AP6 (240VAC, 60Hz) |
| 3TF4422-0AV0 | B3TF4422-0AV0 | 480VAC | 32A | 25HP | 2 NO / 2 NC | B3TY7443-0AV0 (480VAC, 60Hz) |
3TF44 and 3TF4422 are both listed with a 110/120VAC coil, as is the -0AK6 version. The suffixes -0AC2, -0AP6 and -0AV0 are the 24VAC, 240VAC and 480VAC versions. All six share one set of ratings, so the coil is the only thing that separates them.
32A and 25HP are the catalogue values for the BRAH part. Treat them as a check against the rating plate of the contactor you are removing and against the motor nameplate, not as a motor rating worked out for your application. The 44 in the part number is a size code and says nothing about amperes.
Whole contactor, coil, contacts or auxiliary block: which to replace
The catalogue lists the wearing parts of the 3TF44 individually. Use the symptom to decide how much to replace. When the history of the unit is unknown, or more than one part shows damage, a complete contactor is usually the quicker repair.
| Option | When it fits | BRAH part numbers | What the catalogue lists |
|---|---|---|---|
| Whole contactor | Coil and contacts both damaged, cracked housing, or unknown history | B3TF44, B3TF4422, B3TF4422-0AC2, B3TF4422-0AK6, B3TF4422-0AP6, B3TF4422-0AV0 | 3-pole, 600V, 32A and 25HP catalogue rating, supplied with coil and 2 NO / 2 NC auxiliary contacts |
| Coil, type 3TY7443 | Contactor will not pull in or hums, contacts still good | B3TY7443-0AC2 (24VAC), B3TY7443-0AK6 (120VAC), B3TY7443-0AM1 (208VAC), B3TY7443-0AP6 (240VAC), B3TY7443-0AU1 (277VAC), B3TY7443-0AV0 (480VAC) | Listed for 3TF34, 3TF35, 3TF44 and 3TF45. The assembled coil includes its control wiring terminals |
| Contact kit | Main contacts pitted or worn, coil still good | B3TY7440-0A | 3-pole kit, rated 32A, 600V maximum, listed for the 3TF44. Includes all contacts with mounting screws and hardware |
| Auxiliary contact block | Control or interlock contact has failed | B3TY7561-1AA00, B3TY7561-1KA00 | 1 NO / 1 NC side-mount block, listed for 3TF44 through 3TF57 and 3TF68 |
Coils are also listed in 208VAC and 277VAC, which gives a route for a 3TF44 working on one of those control voltages: keep the contactor and fit the coil. Contact kits carry a 6-month warranty, and contactors and other parts carry 2 years from the date of invoice. Signs that contacts are due for replacement are covered in the guide to knowing when a contact kit is needed.
3UA overload relays listed for the 3TF44
The overload relay sits on the load side of the contactor and is chosen by motor current, not by contactor size alone. Four 3UA series in the catalogue name the 3TF44. Within a series, each relay has its own adjustment range, and the motor full-load current has to fall inside it.
| 3UA series | Relays listed | Adjustment ranges, lowest to highest | Contactors named in the listings | Example |
|---|---|---|---|---|
| 3UA52 | 19 | 0.1A to 25A | 3TF32, 3TF33, 3TF42, 3TF43, 3TF44 and 3TB42 to 3TB44 | B3UA52-00-2C (16A to 25A) |
| 3UA54 | 7 | 4A to 36A | 3TF44 and 3TB44 | B3UA54-00-2D (20A to 32A) |
| 3UA55 | 23 | 0.1A to 45A | 3TF34, 3TF35, 3TF44 and 3TF45 | B3UA55-00-2D (20A to 32A) |
| 3UA59 | 24 | 0.1A to 63A | 3TF30 to 3TF35 and 3TF40 to 3TF46 | B3UA59-00-2D (20A to 32A) |
If the existing relay is staying, read its series from the label and confirm the series appears in the table. If it is being changed, replace like for like: same series, same range. Each of these relays is listed with a manual reset button. More detail is in the guide to replacing Siemens 3UA overload relays.
Numbers that look like a 3TF44 and are separate listings
Three neighbours are close enough to cause ordering mistakes. The B3TF34 has the same 32A catalogue rating as the 3TF44 and a different horsepower value, 20HP. The B3TF45 is listed at 38A and 25HP. The B3TB44 replaces the Siemens 3TB44 and is listed at 32A and 25HP with a 110/120VAC coil. Each is a direct substitute for its own Siemens number. Order by the number on your nameplate and do not choose between them by amperage.
Before you order: what to check on a 3TF44
- The complete number. Write down everything on the nameplate, including the four digits and the suffix. 3TF4422-0AC2 and 3TF4422-0AV0 differ only in coil, and one will not work in place of the other.
- Coil voltage. Read it from the coil and from the control circuit drawing. The control supply is often lower than the motor supply.
- Auxiliary contacts in use. The replacement is listed with 2 NO / 2 NC. Note which of them are wired, and whether a side-mount block has been added.
- Motor data. Compare nameplate current and horsepower with the catalogue values in the table.
- Overload relay series and range. Take both from the relay label.
- What has actually failed. A coil that reads open circuit, or contacts that are visibly burnt, may mean a part is enough.
- Fit. Compare the mounting and terminal layout of the installed contactor with the product page before ordering.
BRAH Electric designs these parts in-house and tests them in Carlsbad, California. It is an aftermarket manufacturer and not an authorized Siemens distributor. In-stock orders placed before 3:00 PM Pacific ship the same business day. For anything not in the tables, call (855) 355-2724 with the part number, Monday to Friday, 6AM to 5PM Pacific.
Fitting and testing the replacement safely
Before any work, de-energize the starter, lock out and tag both the power supply and the control supply, and verify the absence of voltage at the contactor terminals. The work is for qualified personnel. Mark each wire as it comes off so the replacement is connected the same way.
After fitting, check that every terminal is tight and that the coil voltage on the new part matches the control supply. Energize the control circuit with the load isolated and watch the contactor pull in and release. Then start the motor and observe the first few operations for chatter, unusual noise or heat. If anything is wrong, isolate again before investigating.
Siemens 3TF44 replacement FAQs
What is the BRAH replacement for a Siemens 3TF44?
The B3TF44, or the B3TF4422 version with the suffix that matches your coil. It is listed as a direct substitute for the Siemens part.
What coil voltages is the 3TF44 replacement listed in?
24VAC, 110/120VAC, 240VAC and 480VAC as complete contactors. Separate 3TY7443 coils are listed in 24VAC, 120VAC, 208VAC, 240VAC, 277VAC and 480VAC.
Can I change only the contacts on a 3TF44?
Yes. The B3TY7440-0A is a 3-pole contact kit listed for the 3TF44, supplied with its mounting screws and hardware.
Which overload relay fits a 3TF44?
Relays in the 3UA52, 3UA54, 3UA55 and 3UA59 series are listed for it. Choose by the series already fitted and by the motor full-load current.
Is a 3TF34 the same as a 3TF44?
They are separate listings. Both have a 32A catalogue rating, and the horsepower values differ: 20HP for the 3TF34 and 25HP for the 3TF44. Order the number on your nameplate.
Are other 3TF sizes replaced the same way?
Yes, the B prefix applies across the series. Sizes, ratings and the suffix table for the whole range are in the 3TF range guide.
References
- IEC 60947-4-1, the IEC standard for electromechanical contactors and motor-starters, which sets out how contactors are rated.
- OSHA 29 CFR 1910.147, the OSHA rule on controlling hazardous energy by lockout/tagout.
- NFPA 70E, the NFPA standard for electrical safety in the workplace, including verifying the absence of voltage.
