Quick Hits

⚡ Quick Hit: Commercial Kitchens Get Their Own Table

NEC Article 120 — “Load Calcs Won't Kill You” 🔌⚡

Episode 22 — 120.56 Commercial Kitchen Equipment

🍽️ THE QUICK HIT

We've just finished working through household cooking appliances under 120.55.

Now we're moving into a different environment:

Commercial kitchens.

Restaurants, cafeterias, institutional kitchens, and similar facilities can have a LOT of electrical equipment operating throughout the day.

Article 120 provides a specific demand-factor method for these loads.

📖 120.56 — WHAT EQUIPMENT DOES IT COVER?

Table 120.56 can be used for qualifying kitchen equipment such as:

• ⚡ Instantaneous water heaters

• 🍳 Commercial electric cooking equipment

• 🍽️ Dishwasher booster heaters

• 🚿 Water heaters

• 🔌 Other qualifying kitchen equipment

WHAT COUNTS AS "OTHER KITCHEN EQUIPMENT"?

For this provision, the equipment must be:

Fastened in place

AND rated:

¼ hp or greater

OR

500 watts or greater

📊 TABLE 120.56 — THE DEMAND-FACTOR METHOD

Table 120.56 provides demand factors for qualifying kitchen equipment.

But there's an important condition before you start applying those factors.

The equipment must have:

🌡️ Thermostatic control

OR

⏱️ Intermittent use

This recognizes that qualifying kitchen equipment may not operate continuously at its full connected load.

🚫 EQUIPMENT THAT DOESN'T USE THIS METHOD

The 120.56 demand factors don't apply to:

🔥 Space-heating equipment

🌬️ Ventilating equipment

❄️ Air-conditioning equipment

Those loads have their own applicable requirements elsewhere.

🔑 DON'T DOUBLE-DIP

Just because equipment happens to be located in a commercial kitchen doesn't automatically mean Table 120.56 applies to it.

You still have to determine whether the equipment falls within the scope of the provision.

🚨 THE FLOOR RULE

Here's the part you really want to remember.

Even after applying the applicable demand factors:

THE CALCULATED LOAD CANNOT BE LESS THAN THE SUM OF THE TWO LARGEST KITCHEN EQUIPMENT LOADS.

Think of it as a safety floor.

🧮 EXAMPLE

Suppose the two largest qualifying kitchen equipment loads are:

Equipment #1: 18 kW

Equipment #2: 12 kW

The minimum calculated feeder/service load would be:

18 + 12 = 30 kW

Even if applying the table's demand factors produces a number below 30 kW:

30 kW is still the minimum.

🎯 TEST YOURSELF

Per 120.56, what is the absolute MINIMUM the feeder/service calculated load must be, regardless of the table demand factors?

A) The single largest kitchen equipment load only

B) The sum of the largest 2 kitchen equipment loads

C) 50% of the total connected kitchen load

D) There is no minimum floor

👇 What's your answer?

🧮 SHOW YOUR MATH

Imagine the two largest qualifying kitchen equipment loads are:

20 kW

and

15 kW

Add them:

20 + 15 = 35 kW

⚡ MINIMUM CALCULATED LOAD

35 kW

The applicable demand-factor calculation cannot reduce the feeder/service calculated load below this floor.

✅ ANSWER

B) The sum of the largest 2 kitchen equipment loads

That's the critical floor rule to remember from 120.56.

🔑 QUICK MEMORY TRICK

Commercial kitchen

↓

Table 120.56

↓

Qualifying thermostatic/intermittent equipment

↓

Apply applicable demand factors

↓

Never below the 2 largest loads combined

⚠️ TABLE 120.56 NOTE

The actual numerical demand factors contained in Table 120.56 were not included in the source material available for this Quick Hit.

Therefore, this page intentionally explains the methodology and minimum-load requirement without inventing or estimating the missing percentages.

For the exact demand-factor values, consult the official NEC and the complete Table 120.56.

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🧭 QUICK HIT NAVIGATION

← Back to Article 120 Quick Hits

← Episode 21 — Single Appliances & Combo Circuits

→ Episode 23 — EVSE Load Calculations

⚠️ EDUCATIONAL NOTICE

This Quick Hit is an educational explanation based on the author's understanding of the NEC. It is not a substitute for the official NEC, applicable local amendments, manufacturer instructions, or the determination of the Authority Having Jurisdiction (AHJ).

Always verify the requirements applicable to your specific installation.

The National Electrical Code® and NEC® are registered trademarks of NFPA. JoshTheSparky.com is not affiliated with, sponsored by, or endorsed by NFPA.