Danfoss DS-824C Installation guide

LIMITED WARRANTY

The DS-824C is warranted against defects in workmanship and materials for two years from date of sale.
This warranty does not apply to damage resulting from accident, misuse, or alteration nor where connected
voltage is more than 5% above the configured operating voltage, nor to equipment improperly installed or
wired or maintained in violation of this Owner’s Manual. No other written or oral warranty applies. No
employee, agent, dealer or other person is authorized to give any warranties on behalf of DANFOSS.

CAUTION: Read all instructions carefully before installation.
Save this Installation Manual for future reference.

DS-824C

Units returned for warranty repair cannot be modified from shipped condition and leads must protrude a
minimum of 6 inches from the base conduit hub. Repair costs of a modified unit will be quoted as the unit
must be returned to the original, unmodified condition prior to return shipping. The customer shall be
responsible for all costs incurred in the removal or reinstallation and shipping of the product for repairs.
Within the limitations of this warranty, inoperative units should be returned, freight prepaid, to DANFOSS,
and we will repair or replace, at our option, at no charge to you with return freight paid by DANFOSS. It is
agreed that such repair or replacement is the exclusive remedy available from DANFOSS and that
DANFOSS IS NOT RESPONSIBLE FOR DAMAGES OF ANY KIND, INCLUDING INCIDENTAL AND
CONSEQUENTIAL DAMAGE. Some states do not allow the exclusion or limitation of incidental or
consequential damages so the above exclusion may not apply to you. The warranty gives you specific
legal rights, and you may also have other rights which vary from state to state.

DANFOSS ELECTRIC HEATING DIVISION
TOLL FREE: 1-888-DANFOSS (326-3677)
Option #3 for heating
FAX: [phone]

Visit us on the Internet at: heating.danfoss.us

RAIN/SNOW SENSOR CONTROLLER

INSTALLATION MANUAL

INDICATOR

OFF

POWER

ENCLOSURE TYPE 3R

RAIN/SNOW SENSOR CONTROLLER

INPUT
22−28V AC/DC 500mA 50/60 Hz
CONTROL
30 A 24V AC, 20 A 28V DC

DS−824C

WARNING: NOT FOR HIGH VOLTAGE CONTROL

AVERTISSEMENT: PAS POUR LE CONTRÔLE DE HAUTE TENSION

ACTIVATED

CONTROL SWITCH

MANUAL ON
AUTOMATIC
STANDBY/RESET

Danfoss Electric Heating Division

General Safety Instructions

1. THIS UNIT SHOULD BE INSTALLED, OPENED, AND REPAIRED BY QUALIFIED PERSONNEL

ONLY!

CETTE UNITÉ DEVRAIT ÊTRE INSTALLÉE, OUVERTE, ET RÉPARÉE PAR LE PERSONNEL

QUALIFIÉ SEULEMENT!

2. To avoid shock hazard do not open the front cover with power connected to the DS-824C or any

controlled equipment. Limit input voltage to 22-28 VAC/VDC

Pour éviter la décharge électrique déconnectez toute la puissance avant d'ouvrir la couverture du DS-

824C. Limiter la tension d'entrée à 22-28 VAC/VDC

Moisture Sensor Mounting & Termination

The remote DS-824C precipitation/moisture sensor may be
mounted in a number of ways depending on the application. The

DRIP EDGE

SENSOR

GUTTER

the sensor. We do not recommend laying the sensor on its side
in the gutter. Constant immersion will corrode the grid and the
sensor may miss a windblown snow trigger.

The sensor cable comes preinstalled but may be shortened as
needed. Strip the outer insulation and shield from the cable and
terminate each conductor following the color code printed on
the circuit board for TB-1; (W)hite, (G)reen, (R)ed, (B)lack. The
bare drain wire should be installed into the (S)hield terminal.
Tighten the strain relief on the DS-824C enclosure. If additional
length is required purchase the EX-50 50 foot extension cable.
Erratic operation may result if the proper cable is not used.

Selecting a Mounting Location for the DS-824C Enclosure

The brass cylinder protruding from the bottom of the enclosure is the temperature sensor. For proper
temperature detection the DS-824C must be mounted outdoors, away from furnace vents and other
sources of heat. Note that, when powered, the DS-824C moisture grid will always remain hot. This is
normal. This allows the sensor to continuously melt snow and evaporate both rain and snow from the grid.

The DS-824 can be mounted by screwing the base conduit hub onto an appropriate size free-standing
conduit or by using the mounting holes in each corner of the enclosure.

sensor head operates at a safe 12VDC and can withstand
immersion in water. For roof and gutter deicing applications the
sensor head may be mounted against the back of the gutter with a
1” “C”-style conduit clamp. Allow part of the sensor grid to be
exposed to snowfall. The sensor will initially trigger when snow
starts falling and will remain triggered as long as the roof/gutter
heater continues to drip melted snow from the roof edge when
temperatures are below freezing. The sensor may also be installed
inside and near the top of the downspout using a 1” conduit
hanger and mounting plate. As water is melted in the gutter it will
run to the downspout,

DOWNSPOUT

hitting and retriggering

SENSOR

MOUNTING

PLATE

1" CONDUIT

CLAMP

2

External Control/Monitor Operation

Pin Color Function

1 White GND/Common
2 Red Deice On Mon A
3 Orange Deice On Mon B
4 Black Manual On
5 Green Standby/Reset

This relay, rated at 24 VAC/VDC at 400 ma, will close with the load relay and can be used to externally
monitor activation of the sensor. This terminal block is also the connection point for installing a CDP-2
interface cable.

The DS-824C provides external control/monitor capability.
Shielded cable can be connected to TB2 to access this feature.
Connecting Black (4) to White (1) will activate the “Manual On”
function. Connecting Green (5) to White (1) will activate the
“Standby/Reset” function. See the “Manual Override Switch
Function” for a description of these modes. The Red/Orange
(2/3) leads are connected to an internal low power monitor relay.

Power & Activation Indicator

A green lamp shines through a lens on the cover of the DS-824C to indicate operational status. If this lamp
is OFF the DS-824C is not receiving power. If this lamp is steady ON the DS-824C is powered but not
triggered. If this lamp is FLASHING the DS-824C is powered on and triggered, the main relay is closed,
and attached equipment should be activated. Note that, even though snow or rain may have stopped, the
DS-824C indicator will continue to flash during the Delay-Off drying cycle.

Preseason Snow Detection Testing

It is always a good idea to test the operation of the DS-824C prior to the winter season. Procure some
clean water and, if the outdoor temperature is above the trigger point, a can of spray component cooler.
Clean the moisture grid following the procedure outlined above and allow it to dry. Apply power to the DS­824C, drip some of the water onto the moisture grid, then spray the temperature sensor protruding from the
base of the enclosure with the component cooler. Once the temperature sensor has reached the trigger
point with water still present on the grid the DS-824C will activate. The user should hear the internal
control relay close and see the green lamp blink. Proper operation has been confirmed. Allow the grid to
dry completely. To clear the Delay-Off timer place the override switch into “Standby/Reset”, and then back
to the “Automatic” position.

Moisture Grid Maintenance & Replacement

It is recommended that the DS-824C be powered down and the grid wiped clean with clear water at least
once every 4 months. Heavy deposits may be removed using a non-metallic scouring pad (Scotch-BriteTM
or equivalent.) However, after a number of years, the corrosive elements left behind when water is
evaporated out of the moisture grid will eventually damage the grid rings. The moisture grid can be easily
replaced by ordering and installing an MG-6 “Moisture Grid Assembly.” Reference the “Moisture Sensor

Mounting & Termination” section for information on replacing the precipitation grid.

Use Care When Replacing the Front Cover. Do Not Pinch the Gasket or Overtighten the Screws.

Maintain your enclosure's integrity and improve reliability

Specify the DANFOSS EX-50 when precipitation sensor extension is required

7