DAVIS Rain Collector Heater User Manual

Rain Collector Heater

Installation Manual

The Rain Collector Heater may be used to protect the Rain Collector’s internal components from freezing and/or to measure the moisture content of snowfall. When the heater is on, it is capable of melting snow at a rate of 1/4'' (6 mm) of liquid precipitation per hour. It may not be able to keep up with larger rates of snowfall.

The rain collector heater warms only the inside of the rain collector and the cone itself.

Please note that we have made every attempt to design and manufacture a safe product, but Davis Instruments assumes no liability for any injury or damage caused directly or indirectly by the installation or use of this product.

Note: Although the nominal heater voltage is not hazardous, a short in the wall

transformer could cause hazardous voltage to appear on the heater wires. For safety, you should always turn the heater’s power unit to the “OFF” position before removing the rain collector’s cone. We also recommend that you unplug the wall transformer before removing the rain collector’s cone.

This instruction manual is designed to take you step-by-step through the process required to install and use your rain collector heater. Please take the time to read through this manual before beginning the process.

Components

The rain collector heater includes the following components. Please make sure you have all listed components before continuing.

• Heater Assembly — Includes heater element, thermostat, and terminal block for power cable.

• Wall Transformer with Power Unit

• Insulation Blanket

• 50' (15 meter) Heater Cable

Components

The Installation Hardware Kit includes:

• Three Cable Ties

• Two #6-32 x 3/4” Screws

• Two #6-32 Hex Nuts

• Two #6-32 Split Lock Washers

• Two #4 x 3/8'' Self-tapping Screws

Heater Assembly

Wall Transformer

with Heater Power Unit

Insulation Blanket

#6-32 x 3/4"

Screws (2)

with Lock Washers

and Hex Nuts

Heater Cable

50' (15 meter)

Cable Ties (3)

#4 x 3/8" Self-tapping Screws (2)

Components

Tools and Materials Needed for Installation

In addition to the components listed above, you will need some of the following tools and materials. Please be sure you have everything you need before beginning the installation.

• Medium Phillips-head and Slot-tip Screwdrivers

• Drill with 5/32” (4 mm) or 3/16” (4.8 mm), and 9/32” (7.2 mm) or 5/ 16” (8 mm) Drill Bits

• Wire Cutter

• Wire Stripper or Knife

• Cable Clips or Weather-Resistant Cable Ties

Installing the Rain Collector Heater

Choosing Cable for the Rain Collector Heater

The rain collector heater comes with a 50-foot (15 m) length of 22 gauge cable. You may use 22 gauge, two-twisted pair wire for cable lengths up to 120 feet (36 m). If you want to use single pair cable, use the following table to determine the minimum wire size for the desired length of cable run.

Length of Cable Run Minimum Wire Size

Up to 60 feet (18 m) 22AWG (0.50 mm2)

60-100 feet (18-30 m) 20AWG (0.75 mm

100-160 feet (30-50 m) 18AWG (1.0 mm

160-250 feet (50-80 m) 16AWG (1.50 mm

)

If the heater cable is routed with any signal cable (i.e. any cable running from a sensor, junction box or SIM), be aware that for cable runs over 50 feet (15 m) the heater cable’s voltage may interfere with sensor voltages in the signal. To prevent this interference, do at least one of the following:

• Use twisted pair for the heater cable or the signal cable.

• Use shielded cable for the heater cable or signal cable (shield must be grounded).

• Keep the heater cable and the signal cable separated by several inches over most of the length of the cable run.

Installing the Rain Collector Heater

The instructions below will take you step-by-step through the procedure required to install the rain collector heater. Make sure the wall transformer is unplugged until you are instructed to plug it in.

Attaching the Heater to the Rain Collector

1. Remove the rain collector’s cone from the base and, if necessary, remove

the mounting screws from the base of the rain collector.

2. If screw holes for the rain collector heater are not already present in the

base, position the heater as shown on the next page (with the terminal block facing away from the bucket) and mark the location of the screw holes on the heater assembly.

Installing the Rain Collector Heater

Earlier versions of the rain collector did not come with built-in holes for the rain collector heater. If your rain collector does not have built-in holes you need to drill them yourself following the instructions below. Otherwise, skip to step 5.

Marking screw holes

3. Using a drill with a 5/32” (4mm) or a 3/16” (4.8 mm) drill bit, drill holes in

the marked locations.

4. Using a drill bit with a large enough diameter to allow your power cable to

pass through, drill a cable hole in approximately the position shown below.

For the provided 50' (15 m) cable, use a 9/32'' (7.2 mm) or a 5/16'' (8 mm) drill bit. The precise location of the power cable hole is not critical.

Power cable hole

+ 8 hidden pages