Documentation :: General :: Generator Requirements

Introduction

In recent years, adding soft serve or frozen beverage machines to food trucks or other mobile outdoor environments for events has become increasingly popular.  Most of these operations require powering the equipment via a generator or other mobile power source.  This article will outline the requirements for running soft serve and frozen beverage machines on a generator in a mobile environment.

Warning:  Operating the machines with insufficient, or inadequate power will cause damage to the machines and expensive machine components like the compressor.  Operating machines while moving (as in a food truck) and/or excessive travel will cause extra abnormal wear and tear on internal components.  Spaceman has very strict warranty requirements for mobile operations, and warranties will require sufficient proof of manufacturing defect for warranty coverage.  Manufacturing defect does not include damage caused by operating the equipment while moving or electrical damage caused by power issues from under sizing a generator.  While it may be possible to run the equipment on a generator smaller than what is recommended below, Spaceman cannot guarantee coverage under the Limited Warranty if you do so.

Note:  This article does not apply to 3-Phase machines.  For 3-Phase requirements, please contact Spaceman Technical support.

Calculating Generator Size

All electrical equipment with motors or compressors will have two power ratings:  Lock-Rotor Amperage (LRA) and Running Load Amperage (RLA).  When electric motors and compressors initially start, they require significant short-term amp draws, this is the LRA.  Once the motor or compressor is up to speed and running, they require significantly lower amp draw to keep running long term, this is the RLA.  Generally speaking, RLA is most important when running off of shore power in a building.  The minimum circuit ampacity (or circuit breaker size) is determined based off the RLA of the entire machine (all motors, compressors, etc. running simultaneously).  This is because the building power and circuit breakers can withstand and support the short-term amp draw during the startup phase of the motor and compressor without issue.  Unlike shore power in a building, generators do not have the ability to handle high spikes of amp draw, and have a limit on the short term power draws when the motors and compressors start up.  With a generator, the LRA is the determining factor for choosing the appropriate size.  

Warning: On the nameplate of all Spaceman models, you will see an RLA and LRA listed for each component.  These are NOT the RLA and LRA for the entire machine.  Please use the chart below for the RLA and LRA to use when calculating an appropriate generator size.

To calculate the appropriate generator size, multiply the LRA for the machine by the nominal voltage for the machine, and add 10%.  This is the smallest recommended generator size (in wattage) that is required to run each machine.  

Example:  SM-6250H has an LRA of 55 Amps, and runs at a nominal voltage of 220V.  The minimum generator size would be:  55 Amps x 220V = 12,100 Watts + 10% = 13,310 Watts required. 

Note:  This calculation assumes no other electrical components will be plugged into this generator (lights, point of sales systems, other appliances, etc.)  This calculation is for running a single machine on a single generator.  You must factor additional components into this calculation as well.  Things get more complicated when running multiple machines or multiple devices on a single generator power source.  Spaceman recommends consulting with an electrician or the generator manufacturer for calculating the minimum generator size required if running multiple machines or devices.

Spaceman Model LRA Chart

* LRA is per-side.  These machines require a larger generator to account for both sides

When operating a mobile operation on a generator, it is important to follow or note the below items:

1. Do NOT let the generator run out of gas.  When a generator runs out of gas, it can send voltage dips or spikes to the equipment.  These electrical variations can cause severe damage to the machine and its electrical components (like the compressor).
   
2. Do NOT start the machine until the generator is up and running consistently.  It is advised to not start up multiple machines or appliances simultaneously if utilizing a single generator for multiple electrical devices.
   
3. Do NOT operate the equipment or have the equipment powered on while on a vehicle in motion.
   
4. Do NOT operate the equipment on inadequate voltage.  Having an undersized generator will cause damage to the machine that is not covered under warranty.
   
5. Operating the machine in an outdoor environment may degrade machine performance if ambient temperatures are not mitigated.  Higher ambient temperatures will result in lower machine output.  Ensure machines have adequate clearance and ventilation.
   
6. Operating machines in a mobile environment tends to result in more frequent cleaning requirements for the condenser and internals of the machine.  You should inspect your condenser and clean regularly to ensure optimal performance.
   
7. Moving the machines regularly can cause components to wear out quicker than normal.  Before operating, you should always inspect the internal of your equipment to ensure belts are tight and aligned, all bolts, screws, and wiring is secure and tight, and that things have not rattled loose inside the equipment.