Davis Instruments Rain Collector User manual

Product #7720
R
AIN
C
OLLECTOR
H
EATER
I
NSTALLATION
M
ANUAL
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. For some weather conditions, it may be necessary to add a lamp or
heater beneath the unit to keep the drains open.
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.
CAUTION: 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 pro-
cess required to install and use your Rain Collector Heater. Please take the time
to read through this manual before beginning the process.

Page 2 Rain Collector Heater
C
OMPONENTS
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
✦
Installation Hardware Kit
✦
Two Tie Wraps
✦
Two #6-32 x 3/4” Screws
✦ Two #6-32 Hex Nuts
✦
Two #6-32 Split Lock Washers
✦
One #8 x 3/8” Screw
✦
One 1/4” Cable Clamp
Components
Heater Assembly
Insulation Blanket
Heater Cable
50' (15 meter)
Cable Ties (2)
Wall Transformer
with Heater Power Unit
#6-32 x 3/4"
Screws (2)
with Lock Washers
and Hex Nuts
Cable Clamp
#8 x 3/8" Screw
#4 x 3/8"
Self-tapping
Screws (2)

Tools and Materials Needed for Installation Page 3
T
OOLS AND
M
ATERIALS
N
EEDED FOR
I
NSTALLATION
In addition to the components listed above, you will need some of the follow-
ing 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
Choosing Cable for the Rain Collector Heater
The Rain Collector Heater comes with a 50-foot (15 m) length of 22 gauge, two
twisted-pair cable. When using this cable, the red and white wires are joined
and used as one wire and the two black wires are joined and used as one wire.
You may use 22 gauge, two-twisted pair wire in this manner 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.
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.
L
ENGTH OF
C
ABLE
R
UN
M
INIMUM
W
IRE
S
IZE
Up to 60 feet (18 m) 22AWG (0.50 mm
2
)
60-100 feet (18-30 m) 20AWG (0.75 mm
2
)
100-160 feet (30-50 m) 18AWG (1.0 mm
2
)
160-250 feet (50-80 m) 16AWG (1.50 mm
2
)

Page 4 Rain Collector Heater
I
NSTALLING THE
R
AIN
C
OLLECTOR
H
EATER
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 mount-
ing screws from the base of the Rain Collector.
2. If screw holes for the Rain Collector Heater are not already present in the base, posi-
tion the heater as shown below (at the edge of the Davis logo imprinted on the base
with the terminal block facing away from the bucket) and mark the location of the
screw holes on the heater assembly.
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

Installing the Rain Collector Heater Page 5
5. Loosen the screw heads on the terminal block.
You will eventually secure the heater cable wires underneath these screw
heads.
6. Secure the heater assembly to the Rain Collector.
For non-Vantage Pro Rain Collectors, secure the heater assembly to the Rain
Collector base using the #6-32 x 3/4” (19 mm) screws, a lock washer, and a
hex nut, as shown below.
Securing the heater in a Non-Vantage Pro Rain Collector
Note: Non-Vantage Pro Rain Collectors consist of Rain Collectors used with all Weather Wizard III,
Weather Monitor II, GroWeather, Health Enviromonitor and Energy Enviromonitor Weather
Stations.
Terminal Block
Rain Collector Heater Terminal Block

Page 6 Rain Collector Heater
For Vantage Pro Rain Collectors, secure the heater assembly to the Rain Col-
lector base using two #4 x 3/8 self-tapping screws, as shown below
7. Using wire strippers or a knife, strip 3/8” (10 mm) of insulation from the heater cable
wires.
8. If you have a Vantage Pro Rain Collector, use a medium size Phillips-head screwdriver
to knock out the hole for the heater’s power cable.
9. Pass the heater cable wires up through the cable hole you just drilled (non-Vantage
Pro Rain Collector) or knocked out (Vantage Pro Rain Collector).
10. If using the provided cable, twist the Red & White wires together to create a single
wire and twist the two Black wires together to create a single wire.
The bare wire may simply be cut off.
#4 x 3/8"
Self-tapping
Screws
Heater
Assembly
Knock-out
Hole for
Heater Cable
Securing the heater in a Vantage Pro Rain Collector

Installing the Rain Collector Heater Page 7
11. Bend each bare wire into a U-shape and secure each one under a screw head on the
terminal block as shown below.
It does not matter which wire goes to each screw as long as only one wire
goes to each screw.
Attaching cables to Terminal Block of Non-Vantage Pro Rain Collector Heater
Terminal Block
Attaching cables to Terminal Block of Vantage Pro Rain Collector Heater

Page 8 Rain Collector Heater
12. Secure the cable to the heater assembly by placing the 1/4” cable clamp over the cable
and securing it to the heater assembly as shown below.
Securing Cable to Heater Assembly
13. To provide strain relief for the cable, place a cable tie around the cable just above the
hole through which this cable is running, as shown below.
You may want to cut off the excess cable tie.
Providing Strain Relief
14. Re-attach (or attach) the Rain Collector to the mounting surface.

Powering the Heater Page 9
Installing the Insulation Blanket
1. Fit the insulation blanket against the side of the Rain Collector cone, pushing it as far
inside the cone as it will go.
If fully inserted correctly, the blanket should extend all the way to the top of
the cone, leaving a space of approximately 5/16” (8 mm) at the bottom to
accommodate the base.
Inserting Insulation Blanket
2. Re-attach the Rain Collector cone (with insulation blanket) to the base.
P OWERING THE H EATER
Running the Cables
Run the heater cable from the Rain Collector to the location at which you plan
to plug in the wall transformer/power unit. To prevent fraying or cutting of
the cable, secure it so that it does not whip about in the wind. Use cable clips or
weather resistant cable ties to secure the cable underneath the eaves of your
house/building, or in a location similarly shielded from rain. Make sure the
cable is secure by placing clips or ties approximately every 3-5 feet (1-1.6 m).
Do not use metal staples or a staple gun. Metal staples, especially when
installed with a staple gun, have a tendency to cut the cables.
Note: If your cable run extends more than 50 feet (15 m), keep the heater cable and the Rain Collector
cable separated by at least a few inches, as discussed in “Choosing Cable for the Rain Collector
Heater” on page 3.
Attaching Cable to Power Unit
1. Remove the base of the power unit by removing the four screws in the base.
2. Loosen the screw heads on the terminal block.
You will eventually secure the heater cable wires underneath these screw
heads.

Page 10 Rain Collector Heater
3. Using wire strippers or a knife, strip 3/8” (10 mm) of insulation from the heater cable
wires.
4. Feed the cable through the hole in the power unit.
5. If using the provided cable, twist the Red & White wires together to create a single
wire and twist the two Black wires together to create a single wire.
The bare wire may simply be cut off or connected to ground if you wish to
make use of the shield in the cable.
6. Bend each bare wire into a U-shape and secure under a screw head on the terminal
block, as shown below.
It does not matter which wire goes to each screw as long as only one wire
goes to each screw.
Power Unit terminal Block
7. To provide strain relief for the cable, place a cable tie around the cable just inside the
hole through which this cable is running as shown below.
You may need to cut off the excess cable tie in order to close the power unit.
Providing Strain Relief
8. Replace the base of the power unit.

Using the Rain Collector Heater Page 11
9. You may now plug the wall transformer into an outlet.
10. To insure that the heater is working, you may want to set the power unit to the “ON”
setting and then go to the Rain Collector to insure that the heater element is hot.
DO NOT TOUCH THE HEATER ELEMENT OR ANY METALLIC POR-
TION OF THE HEATER. You should be able to feel the heat at a short dis-
tance from the heater element.
U SING THE R AIN C OLLECTOR H EATER
You may switch the Rain Collector Heater on and off from the power unit.
✦ OFF
When the Rain Collector Heater is off, the indicator light on the power
unit is also off.
✦
ON
When the Rain Collector 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. When the Rain Collector Heater is
set to “ON,” the indicator light on the power unit is also on.
Note: The Rain Collector Heater warms only the inside of the Rain Collector and the cone. For some
weather conditions it may be necessary to add a lamp or heater beneath the unit to keep the drains
open.
The heater assembly includes a thermostat switch. If the temperature at the
thermostat reaches 110˚F (43˚C) the thermostat will interrupt power to the
heater element. When the temperature at the thermostat drops to about 85˚F
(30˚C) power flow to the heater element will be resumed.
Location of Thermostat
You can turn the heater on when you expect the temperature to drop below
freezing, and turn it off again when you are no longer worried about freez-
ing conditions.

Product Number: 7720
Davis Instruments Part Number: 7395-096
Rain Collector Heater
Rev. D Manual (8/6/01)
This product complies with the essential protection requirements of the EC EMC Directive 89/336/EC.
© Davis Instruments Corp. 2001. All rights reserved.
3465 Diablo Avenue, Hayward, CA 94545-2778
510-732-9229 • Fax: [phone]
E-mail: [email protected] • www.davisnet.com