Standby / Sleep Mode: Keeping your Empty Reefer Ready for Work

The time to discover that your reefer battery is dead, or the engine too cold to start, isn't an hour before your pick, as you are stocking your truck from that last bit of home time you just had. Heck, in the winter time, if your battery isn't the greatest, all it may take is running a dry load for a week in the snow / ice before it's zapped.

Not anymore! Put your reefer to sleep, and your worries to rest.

Most modern microprocessor controlled reefer units have a program built into them called Standby, or Sleep mode, depending on the manufacturer. This mode is intended to allow the operator to shut down the unit, but have it monitor the ambient outdoor temps, as well as the battery voltage, and start the reefer engine if either of those parameters falls outside of the preset values. For example, on my Carrier Ultima XTC (2005 year), when I put it into sleep mode, if the voltage gets low, or the temperature is freezing (or below) for several hours, the unit wakes itself up, and runs the engine until the battery is charged / engine is warm. For Idaho winter conditions, this usually means the unit will wake up about every 36-48 hours and run for an hour or so. In the summer, it won't wake up for a week or more.

CAUTION: When in sleep / standby mode, the box temps aren't regulated! In other words, don't use sleep mode with a loaded trailer of temp-controlled product. It's not to help you sleep!

It's easy to activate sleep mode. On my Carrier unit it's as simple as a few presses of the keypad (see image below). When it's set, my remote indicator lights go to Orange (I have the LED style), and the LCD display indicated that it is in sleep mode. Your unit may run for a while before actually going to sleep, so be patient.

Here's the user manual for Carrier models Ultima 53, Ultra/UltraXL, Extra, Ultra/Ultima XTC with Advance Microprocessor: Link to PDF.

On page 20, you'll find instructions for sleep mode on these particular units (click image to enlarge):

 

Aye. I love running frozen product during the winter! I hear ya on the battery price. You get what you pay for. I run Optima batteries in all of my work equipment, including the reefers.