WarmlyYours PD Pro Snow Switch User Manual

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Snow Switch® Model PD Pro

Instruction Manual

This manual refers to the Snow Switch® Model PD Pro control panel manufactured
since October 31, 2013, which uses a universal (100 – 277 VAC; 50/60 Hz) power supply.
Older units use a voltage-specific power supply and have different wiring configurations.

SAFETY INFORMATION AND WARNINGS

Abnormal Odor or Smoke

In the event of smoke or a burning or abnormal odor, immediately interrupt power to the unit by
unplugging the unit or by turning off the circuit breaker protecting the unit.

Electrical Shock / Fire Hazard

Even when the heat tapes are disconnected, as long as the circuit breaker is on and power is running to
the unit, voltage is still being applied to the yellow heat tape leads. Therefore, never touch the ends of the
yellow leads or let the two leads touch each other. Do not let the two yellow heat tape leads contact any
component inside the unit.

Any installation involving electric heater wiring must be grounded to earth to protect against shock and
fire hazard. Suitable ground fault detection and interrupting systems must be in use at all times to reduce
shock and fire hazard and to protect equipment.

Electric wiring to heating elements must be installed in accordance with National Electrical Code (NEC)
requirements and all other local and applicable electrical codes and any third party standards. Follow the
installation instructions contained herein and those provided by the heater manufacturer.

Use a GFEP (Ground Fault Equipment Protection) circuit breaker on each branch circuit connected to the
ice melting system. Clearly label each circuit breaker with its function. This is vitally important when
there is more than a single point of disconnect.

Size the circuit breaker in accordance with the size of the expected load. The maximum current load for
the PD Pro is 30 Amp resistive. The PD Pro often serves as a pilot duty relay for operating high current
single- or three-phase contactors in residential or light commercial applications. This product is intended
for use in residential or light commercial applications. For larger or more critical installations, the “APS”
Series of control panels from Environmental Technology, Inc., provides a cost-effective solution offering
enhanced system design and performance features.

Make certain that the heater shield is properly grounded. Failure to do so may result in damage to the
equipment or fire.

Following installation, and prior to beginning system operation, refer to and perform the Post-Installation
Tests described in this manual.

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READING

Check heat tape manufacturer’s documentation.)

SYSTEM CURRENT (Amps)

system breaker sizing)

Snow Switch® Model PD Pro

Instruction Manual

PRODUCT TESTING RECORD

Use this page to record the results of the testing procedures in this manual. Specifically, these
are a mega-ohm test following installation of the heat tape, a post-installation test of the control
box, and a post-installation test of the system sensor(s). This record will be a useful resource
throughout the life of the product.

MEGA-OHM TESTING (Page 10)

(Follow heat tape manufacturer’s recommendations or, if not available,

use a 500 VDC mega-ohm meter on the heat tape.)

TEST

DATE

TEST

DATE

AMBIENT

TEMPERATURE

POST-INSTALLATION CONTROL TESTING (Page 15)

(Use a voltmeter or clamp-on amp meter on either yellow control lead.)

SUPPLY VOLTAGE (Volts)

AMBIENT

TEMPERATURE

POST-INSTALLATION SENSOR TESTING (Page 16)

(Use a voltmeter on the leads indicated.)

If heat tape is disconnected.

(Use voltmeter.)

(Target: faceplate voltage)

Sensor Supply Voltage Sensor Control Voltage

(Target: 20 MΩ or greater;

If heat tape is not disconnected.

(Target: should be based on heat

consult heat tape supplier;

reading must be less than

faceplate amps and

(Use amp meter.)

tape used,

TEST

DATE

AMBIENT

TEMPERATURE

Red to Black White to Black

Warm & Dry

(Target: 23 – 28 VDC)

(Target:

22 – 28 VDC)

Cold & Wet

(Target: less than

2 VDC)

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Snow Switch® Model PD Pro

Instruction Manual

TABLE OF CONTENTS

SECTION PAGE

Safety Information and Warnings --------------------------------------------------------------- 1

Product Testing Record ------------------------------------------------------------------------- 2

Unpacking the Unit ----------------------------------------------------------------------------- 4

Inventory ---------------------------------------------------------------------------------------- 5

Product Description ----------------------------------------------------------------------------- 5

Selecting the Proper Sensor -------------------------------------------------------------------- 6

Available Optional Components ----------------------------------------------------------------- 6

Installing the Control ---------------------------------------------------------------------------- 8

Preparation and System Set-Up ---------------------------------------------------------------- 9

System Schematic Diagrams ----------------------------------------------------------------- 11

Post-Installation Testing ---------------------------------------------------------------------- 14

Operation -------------------------------------------------------------------------------------- 18

Optional Remote Control Operation ----------------------------------------------------------- 21

Maintenance ---------------------------------------------------------------------------------- 22

Troubleshooting ------------------------------------------------------------------------------ 23

Heater Connection ------------------------------------------------------------------------------ 28

Specifications --------------------------------------------------------------------------------- 29

Ordering Information -------------------------------------------------------------------------- 30

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Snow Switch® Model PD Pro

Instruction Manual

UNPACKING THE UNIT

Immediately upon receipt, inspect the container and packing material for any noticeable damage.
Unpack the unit, taking care not to damage the packing materials. Save the shipping container
and related materials until normal operation has been established. If the unit must be returned,
take care to ensure that it is repackaged as it was received.

As soon as the unit arrives at your facility, inspect it for mechanical damage. If any of the
following problems is found, contact Environmental Technology, Inc., Customer Service
immediately:

• contents incomplete or incorrect;

• internal or external mechanical damage; or

• defective operation.

ETI Customer Service is available between 8:00 a.m. and 5:00 p.m. Eastern Time at (574) 233­1202 or [phone]. In the event of shipping damage, keep the packing materials for
inspection by the carrier.

RETURNS AND REPLACEMENT PART PURCHASES

Equipment cannot be returned for credit once it has been installed. ETI will repair or replace
faulty equipment under warranty. Prior to removal of equipment for warranty return, please
contact ETI Technical Support at [phone] for troubleshooting assistance.

Before returning a unit to Environmental Technology, Inc., obtain a Return Merchandise
Authorization from our Customer Service Department, available between 8:00 a.m. and 5:00 p.m.
Eastern Time at [phone] or [phone]. If possible, use the original container and
packing materials when packing the unit for shipment. It is important to mark the Return
Merchandise Authorization clearly on the outside of the shipping container so that it may be
correctly processed upon receipt at Environmental Technology.

For more information about replacement parts or for a replacement Data Sheet or Manual, please
visit http://www.networketi.com/.

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Snow Switch® Model PD Pro

Instruction Manual

INVENTORY

Using the information below, verify that the shipping package contains all of the parts listed.
Notify Environmental Technology, Inc., Customer Service immediately if there are any
discrepancies. Environmental Technology, Inc. Customer Service is available between the hours
of 8:00 a.m. and 5:00 p.m. Eastern Time at [phone] or [phone].

Item Number Item Description

1 PD Pro
2 Accessory Kit
3 PD Pro Installation Sheet

4

PD Pro Instruction Operation Manual

(this document)

Depending on the specifics of your order, there will also be up to two sensors included with the
system, as well. These will be either the CIT–1 aerial-mount sensor, the GIT–1 gutter ice sensor,
or the SIT

–6E pavement-mount sensor.

PRODUCT DESCRIPTION

The Snow Switch model PD Pro snow and ice control, when used with up to two compatible
sensors, automatically controls snow and ice melting heaters for minimal energy costs.
Applications include pavement, sidewalk, loading dock, roof, gutter, and down spout snow/ice
melting in commercial and residential environments. The PD Pro control is powered from
operating voltages of from 100 to 277 VAC and is rated for 7 amps inductive load. Additionally,
the PD Pro is rated for 30 amps resistive load.

The PD Pro control is housed in an environmentally-sheltered IP 66, NEMA 4X weather-resistant
enclosure to provide several installation options.

Features and Benefits

• Compatible with standard CIT–1, GIT–1, and SIT–6E sensors

• Two sensor input to allow for application specific sensor combination such as:

o A CIT–1 aerial sensor and a GIT–1 gutter sensor for roof and gutter deicing
o A CIT–1 aerial sensor and SIT–6E pavement-mounted sensor for snow melting

• Adjustable 0 – 8 hour hold-on time

• Compatible with the RCU–3 remote control

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One or two CIT–1 Sensors

One GIT–1 Sensor

One GIT–1 and one CIT–1 Sensor

One SIT–6E Sensor and one CIT–1 Sensor

Snow Switch® Model PD Pro

Instruction Manual

• Durable IP66, NEMA 4X enclosure

• UL Listed to UL 873 Temperature-Indicating and -Regulating Equipment

SELECTING THE PROPER SENSOR

The Snow Switch model PD Pro snow and ice control is designed for use with up to two
compatible sensors. Compatible sensors include the CIT–1, GIT–1, and SIT–6E snow and ice
melting sensors. These sensors have provided the industry’s most versatile and cost effective
snow melting control when used with Environmental Technology control panels. Sensors should
be selected to best suit the intended application.

The CIT–1, GIT–1, and SIT–6E snow and ice melting sensors combine to reliably detect snow and
ice in gutter and pavement applications. The CIT–1 sensor may be paired with either the GIT–1
sensor for gutter applications or the SIT–6E sensor for pavement applications. These sensors
detect precipitation as snow at temperatures below 38°F (3.3°C). Control panels are signaled
only if moisture occurs below this temperature, saving energy and ensuring reliable melting.

Table 1 below presents the recommended sensor combinations for use with the PD Pro snow
and ice control.

Table 1. RECOMMENDED SENSOR COMBINATIONS.

For more complete information regarding the sensors and their individual capabilities, refer to the
Products link on the Environmental Technology website, http://www.networketi.com.

AVAILABLE OPTIONAL COMPONENTS

Prior to installation and set-up, it is first useful to discuss two important optional components
available for the Snow Switch PD Pro system. The first of these optional components is a
Remote Control Unit, RCU–3 (Part Number 21357), which allows remote operation of the system
away from the control box. The second optional component is a Temperature Sensor Assembly
(Part Number 19272) which regulates the heating cycle to make it more efficient. Neither of
these optional components comes with the basic system so either or both of them must be
ordered separately and installed along with the system, not only to facilitate their installation but
also to optimize their performance.

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Order Number

Description

21357

Optional Remote Control Unit RCU–3

19272

Optional Temperature Sensor Assembly

Snow Switch® Model PD Pro

Instruction Manual

With the Remote Control Unit, RCU–3, the operator is able to access the full range of system
functions and controls from a second location. With the RCU–3, the operator can manually set
the Cycle Time, equivalent to the Hold-On Time setting on the face of the unit itself, or manually
initiate or terminate a heating cycle. The capability for remote operation is especially useful if
the control box is installed either outside or in a location of the building not easily or readily
accessible by office personnel who may well be in a better location than building maintenance
personnel to assess the need to melt ice or snow from walkways or parking areas.

Also available for the PD Pro system is an optional temperature sensor assembly which senses
the temperature at the cable end and regulates the Hold-On Time period once precipitation has
ended and the call for heat has passed. Installed with the cable end placed at or near the heat
tape, the optional temperature sensor assembly or thermistor is a high-temperature shut-off and
regulates the Hold-On Time period by automatically suspending an active heating cycle if at any
time during that cycle, the temperature at the sensor end rises to above 45°F. Then, if, during
the Hold-On Time period, the temperature drops to below 44°F, the heating cycle will resume
automatically and continue until the end of the Hold-On Time period as set on the face of the
unit. This not only lowers system operating costs but also protects the heat tape from over­heating.

As the placement of the RCU–3 remote control unit is a key factor in the overall configuration of,
as well as customer satisfaction with, the PD Pro system, it is important that it be installed as
part of the system initially. Similarly, as the temperature sensor assembly monitors the
temperature at the point of the cable end to keep the heat tape from over-heating, so it is
necessary, for best results, to lay the temperature sensor at the same time as the heat tape to
ensure proper placement and routing. It is not recommended to try and retrofit either of these
optional assemblies once the system is already installed and operational.

To ensure proper installation and to facilitate placement, wiring, routing, and function of either or
both the RCU–3 or the temperature sensor, it is strongly advised and suggested that these
assemblies, whether together or individually, be installed with the system initially rather than
retrofitted afterwards. Use the information below to order either or both of these important
optional components.

To order either or both of these optional components for your system, contact the Environmental
Technology Sales Department between the hours of 8:00 a.m. and 5:00 p.m. Eastern Time at
[phone] or [phone].

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Top

Right Side View

Snow Switch® Model PD Pro

Instruction Manual

INSTALLING THE CONTROL

Install this unit in compliance with National Electrical Code (NEC) standards, as well as all other
local and applicable electrical codes for your area. Prior to beginning installation, make sure that
the facility has properly sized electric service and breaker. For additional information regarding
electrical ratings and facility power requirements, refer to the Specifications section of this
manual.

This unit is intended for wall mount installation only. The wall used for the installation should be
capable of supporting four times the weight of the unit, or about 20 pounds. Install the unit
directly to a solid, stable surface. The IP 66, NEMA 4X weather-resistant enclosure can be
installed either inside or outside.

Internal connections for any optional remote control unit or system sensor(s) will be made in the
next section.

The dimensions shown in the Top View of Figure 1 below are for the mounting hole location
footprint and run from centerline to centerline of the four slotted mounting holes. The dimension
shown in the Right Side View of Figure 1 is from the bottom of the enclosure to the top of the
clear plastic lid and shows the distance that the unit will protrude from the mounting surface.

Figure 1. PD Pro MOUNTING HOLE FOOTPRINT.

View

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Snow Switch® Model PD Pro

Instruction Manual

To install the control box, perform the steps below.

NOTE

During installation, leave all mounting hardware loose enough to allow for slight adjustments to
component placement. Once all components and the front panel and clear plastic cover have
been installed, then, as the final step in installation, fully tighten all mounting hardware and
weather-tight fittings. Make sure all connections and fittings are snug, air-tight, and water-tight.

1. Use the box as a template to determine the mounting hole footprint pattern. Hold the
unit up against the wall onto which it will be mounted, with the mounting blocks against
the wall, then mark the wall at the locations of the slotted mounting holes to determine
the location of the mounting holes on the wall.

2. As desired, to hold the box in place during the installation process, you may loosely
install one or both of the top mounting bolts as the remaining holes are marked. To
ensure accurate and level installation, however, do not fully tighten any of the mounting
hardware until all hardware has been started.

3. Once the four mounting holes have been located and marked, install the box to the wall
using properly sized mounting hardware. Be sure to use mounting hardware appropriate
for the job, heavy-duty and long enough to fasten the unit securely to the mounting
surface. Make sure to use all four mounting holes. Because conduit will also be
installed to protect the cables running from the control box, install the box, but leave the
mounting hardware loose enough to work the conduit into place. The conduit will be
installed later in this process, at which time all mounting hardware will be securely
tightened.

PREPARATION AND SYSTEM SET-UP

Install the conduit, system sensor(s) and sensor cables, heater cables, and power cable. Refer to
Figures 2 and 3, as well as Table 2. Remove the clear plastic unit cover and face plate to access
the inside of the unit. These will be replaced at the end of the installation process. A post­installation test will be performed in the next section to verify proper function.

NOTE

During installation, leave all mounting hardware loose enough to allow for slight adjustments to
component placement. Once all components and the front panel and clear plastic cover have
been installed, then, as the final step in installation, fully tighten all mounting hardware and
weather-tight fittings. Make sure all connections and fittings are snug, air-tight, and water-tight.