A Coffee Roaster Wiring Question

JHCCoffee

Electrical Wiring Question

I’m getting my electrical panel, breaker, circuits and plug outlets ready for the Fresh Roast SR800 with Extension Tube. It apparently can consume 1,750 watts / 120 volts (Canada) = 14.5 amps, minimum. According its been recommended that I plug into a 20 amp circuit dedicated to the roaster. So I identified a spot on my electrical panel for a 20 amp breaker, which I will connect to 12 gauge wiring (to safely handle the 20 amps), which I will connect to a dedicated receptacle/outlet.

I have three choices for the receptacle: Option 1) a standard 15 amp 2 plug receptacle , Option 2) a 20 amp 2 plug receptacle, which by definition has 1 straight and 1 cross shaped female slot that will accept a 20 amp plug with a similar shape. However using an appliance designed for 15 amps (including its 15 amp cord) on a 20 amp breaker may not be wise. So Option 3 is a dedicated 15 amp breaker connected to a 15 amp receptacle.

@DavecUK and anyone with electrical engineering knowledge. What would you do? Further information on each wiring option is provided below.

Option 1 is to use the existing FR800 plug and a 15 amp receptacle, connected to 20 amp rated wiring (12 gauge) and a 20 amp breaker. In this case does the plug outlet then becomes the weak point in the system?

Option 2 means that I would have to cut off the existing end plug of the SR800 and replace it with one designed for 20 amp use (with the cross shaped prong). The result would be a completely 20 amp wiring setup, from the roaster to the circuit breaker.

I think it would be best (safest) to use a 20 plug into a 20 amp plug receptacle. Which means cutting/replacing the SR800 plug. But I am nervous about cutting the FR SR800 wire, particularly as it is a multi strand wire and it is easy to lose some strands. I can and will if that is the best/safest course of action.

Option 3 is a dedicated 15 amp (not 20) breaker connected to a 15 amp receptacle. The actual coffee roaster wire is (I believe) rated for 15 amps, within a heat resistant shield. While I know that many folks connect their FR SR800 roasters to 20 amp breakers (given their high wattage), is it not risky to have the potential for amperage to spike to 20 amps along a 15 amp wire before the breaker trips? Should I stay with a 15 amp breaker and ensure that it is 100% dedicated to the roaster?

Thoughts? What’s the best / safest route?

JHCCoffee

PS. I’m getting conflicting information on whether the roaster wire and plug is rated at 15 amps or 20 amps. So I emailed the manufacturer. Stay tuned.

JHCCoffee

Fyi the wire is 16AWG, but seems to be quite thermally insulated (for coffee roaster use). The manufacturer says I should use a 20 AMP breaker (to avoid voltage drop) but I am curious as to why its ok to do that with what is clearly well below 15 amp wire.

Also the Extension Tube allows one to achieve higher temps at the same temperature setting, so I probably don’t need the extra amps

Gagaryn

This is why fused plugs are a good thing on individual appliances - they serve as protection for the flex lead which is a common cause of fires.

You seem to be getting a lot of dubious information and advice. I can’t see any reason why the breaker size would contribute to voltage drop. Cross section of the wire used could contribute to voltage drop, directly related to the length of cable. The safest thing to do, IMHO, would be to use the 12 gauge wire you had planned with a 15 amp breaker. That way you have appropriate breaker protection for the appliance and wiring that is less likely to contribute to power loss.

JHCCoffee

Gagaryn The safest thing to do, IMHO, would be to use the 12 gauge wire you had planned with a 15 amp breaker. That way you have appropriate breaker protection for the appliance and wiring that is less likely to contribute to power loss.

Totally agree.

I received the following information from the engineering team at FreshRoast Home Roasting:

“In normal operation , rated current is 14.5A (1750W/120V=14.5A) ,

while rated current of cord spec is 15A for 16AWG wire.

There is no such 20 A across the unit and cord in normal operation.

For abnormal situation, in case of short circuit that causing high current than 15A .

In case, the high current (>15A) that across the cordis very short period of time( less than 0.1sec), not sufficient time to heat up the cord that with rated temperature of 105C.”

Given the above I have wired a 15 amp receptacle to a 15 amp breaker on my panel using a short (3 foot) run of 12 gauge wire. Voltage is excellent at 123.5V. While that will handle 1,850 watts, the appliance cord is rated for 1,750 which at 123.5V says I should not go above 14.1 amps, max.

While the appliance cord is only 3 feet, it would not be safe to connect it to a 20 amp breaker, as that has the potential to draw 2,470 watts (20 amps x 123.5V) on a 16 AWG appliance cord rated for 14.5 Amps and 1,750w. So there is absolutely no way that I am prepared to connect a 16 AWG appliance cord to a 20 amp breaker!

They clearly under spec’d their cord, as I understand that roasters have been challenged to get as dark a roast as they would like unless they use an extension tube. We will see how I do. If I do need more wattage I will upgrade the appliance cord to 12 AWG and change my breaker to 20 amps.