Understanding the Difference Between LC1K06 and LC1K09 Contactors

The Telemecanique LC1K06 and LC1K09 are 3-pole TeSys K contactors, and the only catalogue rating that separates their BRAH Electric replacements is horsepower: the BLC1K06 is listed at 3HP and the BLC1K09 at 5HP. Both are listed at 20A and 600V, with the same four coil voltages and the same choice of one normally open or one normally closed auxiliary contact. Choose by the motor the contactor switches, then by coil voltage and auxiliary contact.

The tables below put the two replacements side by side, list every coil-voltage variant of each, and show the overload relays, coils and auxiliary contacts that the catalogue lists for both sizes.

LC1K06 vs LC1K09 at a glance

• Horsepower is the difference. The catalogue lists the LC1K06 replacement at 3HP and the LC1K09 replacement at 5HP.
• Amperage does not tell them apart. Both are listed at 20A, which reads as a general current rating and not a motor rating. Use the horsepower figure and the nameplate.
• Each size has 11 listings: coils of 24VAC, 120VAC, 240VAC and 480VAC, each with 1 NO or 1 NC auxiliary contact.
• The BRAH part number is the Telemecanique number with a B in front. LC1K0910-B7 is replaced by BLC1K0910-B7.
• The same LR2K overload relays, LX1KK coils and LA1K auxiliary contacts are listed for both. Browse all replacement contactors.

Side-by-side: BRAH replacements for the LC1K06 and LC1K09

The values come from the catalogue records of all 11 listings of each size. The base parts are the BLC1K06 and the BLC1K09.

Two listings of each size also print horsepower by supply voltage in their description. For the LC1K06 replacement (BLC1K0610) and the LC1K09 replacement (BLC1K0910) the figures are:

Read the 20A figure as a catalogue value. It is the same on both sizes, and on the LC1K12 as well, so it cannot be the motor current each one is meant to switch. Do not take a rating from the digits in the part number either. Match the replacement to the nameplate of the contactor you are removing and to the horsepower and voltage on the motor nameplate.

Coil-voltage variants of each size

Each row is one Telemecanique order number pattern and the BRAH part that replaces it in each size. The digits after the size give the auxiliary contact as the catalogue lists it: 10 for one normally open, 01 for one normally closed. The letters after the dash give the coil.

Three things stand out in that table. A number with no dash suffix is listed with a 120VAC coil. The bare numbers LC1K06 and LC1K09 are listed with one normally closed auxiliary contact, the same as the 01 versions. And the -G7 listings carry the same 120VAC coil as the numbers with no suffix, so LC1K0910 and LC1K0910-G7 are listed with the same coil voltage and auxiliary contact. If the number on your contactor ends differently, call (855) 355-2724 with the part number.

Can an LC1K09 replace an LC1K06?

Electrically, a contactor with a higher horsepower rating can switch a smaller motor, and in the catalogue the two sizes share coil voltages and auxiliary contact arrangements. That makes the LC1K09 replacement a workable substitute for an LC1K06 when the coil voltage and auxiliary contact match. The reverse is not safe: an LC1K06 replacement on a motor that needs an LC1K09 is undersized, and undersized contacts overheat and wear quickly.

Two cautions apply. First, the overload relay protects the motor and is set to the motor full-load current, so changing the contactor size does not change the relay setting. Second, a panel built to a drawing should be repaired to that drawing. Fit the same size that came out unless the load has changed or the person responsible for the design agrees to the change.

Parts the catalogue lists for both sizes

Because the two contactors belong to the same TeSys K group, the parts around them are shared. The last column quotes the contactors named in the catalogue description of each part.

The LX1KK coils are listed in 24VAC, 48VAC, 110VAC, 120VAC, 240VAC, 380VAC, 440VAC. In those coil numbers the last digit follows the frequency in the description: 5 for 50Hz, 6 for 60Hz and 7 for 50/60Hz. Pick the overload relay by the motor full-load current, not by the contactor size. See overload relays, magnetic coils and auxiliary contacts, and the guide to troubleshooting an overload relay if the relay is the part that is tripping.

Related TeSys K contactors: LC1K12, LC2K and LP1K

Three neighbours are easy to confuse with these two. The BLC1K12 replaces the LC1K12 and is listed at 7.5HP with the same 20A catalogue amperage and the same coil options. The LC2K06 and LC2K09 are the reversing versions, replaced by the BLC2K06 and BLC2K09; the guide to checking an LC2K09 replacement covers them. The LP1K06 and LP1K09 are listed with DC coils (24VDC, 120VDC and 240VDC), replaced by parts such as the BLP1K0610 and BLP1K0910. An LP1K and an LC1K of the same size are not interchangeable without changing the control supply.

Before you order: what to check

• Size. Read LC1K06 or LC1K09 from the nameplate. The two look alike, so do not judge by appearance.
• Motor. Compare the motor nameplate horsepower and voltage with the catalogue horsepower: 3HP for the LC1K06 replacement, 5HP for the LC1K09 replacement.
• Coil voltage. Read it from the coil marking and the control circuit drawing. The catalogue lists 24VAC, 120VAC, 240VAC and 480VAC for both sizes.
• Coil type. LC1K numbers are listed with AC coils and LP1K numbers with DC coils.
• Auxiliary contact. Check whether the built-in contact in use is normally open (10) or normally closed (01). A holding circuit normally uses the normally open contact.
• Fit. Compare the mounting and terminal positions of the installed contactor with the photos and drawings on the product page before ordering.

BRAH Electric designs its parts in-house and tests them at its Carlsbad, California facility. It is an aftermarket manufacturer and is not an authorized Telemecanique or Schneider Electric distributor. Contactors carry a 2-year warranty from the date of invoice. In-stock orders placed before 3:00 PM Pacific ship the same business day.

Safety when swapping a TeSys K contactor

A small contactor still has line voltage on its power terminals, and the coil may be fed from a separate control source. De-energize the equipment, apply lockout/tagout to every source, and verify the absence of voltage before touching the terminals. The work is for qualified personnel. Mark each wire before you remove it.

LC1K06 and LC1K09 FAQs

What is the main difference between the LC1K06 and the LC1K09?

Horsepower. The BRAH replacement for the LC1K06 is listed at 3HP and the replacement for the LC1K09 at 5HP. The other catalogue ratings are the same.

Why do both show 20A in the catalogue?

The catalogue amperage for these TeSys K contactors is the same across the LC1K06, LC1K09 and LC1K12. Treat it as a catalogue value and size the contactor by horsepower and by the nameplate of the part you are replacing.

Are the LC1K06 and LC1K09 the same physical size?

They belong to the same TeSys K group and take the same coils, overload relays and auxiliary contacts in the catalogue. Confirm the fit for your panel against the product page of the exact part.

What does the -B7 or -U7 at the end of the number mean?

It identifies the coil. In the catalogue, -B7 is listed as 24VAC, -G7 as 120VAC, -U7 as 240VAC and -T7 as 480VAC.

Do I need a different overload relay if I change from an LC1K06 to an LC1K09?

Not because of the contactor. The LR2K relays in the catalogue name both sizes. The relay range must cover the motor full-load current, so it changes only if the motor does.

What happens if the contactor is too small for the motor?

The contacts run hot, wear faster and can weld. Replace it with the size the motor needs.

References

• IEC 60947-4-1, Low-voltage switchgear and controlgear: electromechanical contactors and motor-starters. The standard that covers contactor ratings and utilization categories.
• OSHA 29 CFR 1910.147, The control of hazardous energy (lockout/tagout).
• NFPA 70E, Standard for Electrical Safety in the Workplace.