Hukseflux SPD01 Surge Protection Device For Digital Pyranometers User Manual

Hukseflux SPD01 Surge Protection Device For Digital Pyranometers User

Manual

Cautionary statements

Cautionary statements are subdivided into four categories: danger, warning, caution and notice according to the severity of the risk.

Introduction

Give your pyranometers the protection they deserve! SPD01 is a surge protection device for digital pyranometers communicating over RS-485. The SPD01 reduces the risk of costly instrument damage and data loss, by serving as an additional layer of external protection against high-impulse currents and voltages – surges- for connected devices. For example, seasonal lightning and inductive switching are common sources of surge in PV power plants.

SPD01 features are

• Increased protection of digital pyranometers
• Protection of up to 3 connected instruments
• Up to 4 kV surge protection (IEC 61000-4-5 Class 4)
• Passive device: no power required for protective functionality
• Rugged, weatherproof (IP66) housing
• Designed for Hukseflux-brand “industrial pyranometer” series

Figure 0.1 SPD01, installed on a mast, protecting two SR300-D1 pyranometers.

Immunity to high impulse voltages and currents – surges

SPD01 is a surge protection device for pyranometers. It is designed for use with the Hukseflux-brand “industrial pyranometer” series of instruments. The device combines and coordinates the protection of the power supply and the RS-485 serial communication lines. Protection of the pyranometer against electrical surges is very important to guarantee reliable operation in harsh “industry grade” environments such as solar (PV) power plants. Hukseflux industrial pyranometers are tested and classified for Industrial Environments according to IEC 61326-1 and IEC 61000-6-2.

Why add an SPD?

Pyranometer users may attain several levels of immunity when designing a measurement system. For example, the surge immunity of SR300-D1 industrial pyranometer is level 3 (up to 2 kV surges) according to IEC 61000-4-5. Adding the Surge Protection Device SPD01, the immunity is extended to level 4 (up to 4 kV surges).

To attain the required level of immunity for a given installation, some general system components should be included, such as:

• lightning protection system
• earthing and grounding network
• external surge protection in addition to the native on-board sensor protection

SPD01 properties

In the electrically harsh environment of PV power plants, SPD01 protects connected instruments from lightning – and power-switching induced surge events. At the same time, it allows for a flexible system design. By properly installing the SPD01 near a Hukseflux industrial pyranometer, it assures that voltages and currents reaching the sensor are strongly suppressed.

System design

Provided that instruments are in close proximity to the SPD, up to 3 instruments can be protected by a single SPD01.\

• Instruments are protected from surges in the grounding system
• The distance between the instrument and SCADA system may be increased significantly

Depending on the system design and instrument location, multiple SPD01’s may be used.
In some cases, for example, on-array installation of pyranometers, it is beneficial to isolate the instruments from the mounting platform. Hukseflux supplies an optional accessory for this, the PID01 Pyranometer Isolation Disc, see 2.5.2.

Suggested use

Suggested use for SPD01:

• PV system performance monitoring
• scientific meteorological observations
• When cables exceed 3 meters

SPD01, sacrificial device

SPD01 is built to last. It will survive multiple surges. It is a sacrificial device. In case SPD01 the most likely failure mode is:

• that communication with the protected pyranometers through the SPD01 is no longer possible
• that protected pyranometers are disconnected from power and RS485
• that the protected pyranometers are still in working condition
• that the protected instruments are still protected against surges
• that SPD01 is no longer working and must be replaced by a new

Lightning protection

Any outdoor installation is vulnerable to lightning strikes. To reduce the risk of permanent damage we advise to install lightning protection. Lightning strikes can be direct or indirect. Damage from direct lightning strikes can be avoided by installing lightning rods. The appropriate location and height of these rods follows from a lightning risk analysis.

Figure 0.2: Hukseflux industrial pyranometers should be installed in LPZ2. Hukseflux SPD01 is a type 2 SPD which is used on the zone boundary from LPZ0b to LPZ2.

Damage from indirect lightning strikes results from electrical surges through the mounting structure and cabling attached to the pyranometer and SCADA system. To reduce the risk of damage from indirect lightning strikes, appropriate surge protection is required. The lightning risk analysis provides guidance for selecting the correct type of SPD.

In general, the Hukseflux industrial pyranometers should be installed in lightning protection zone 2 (LPZ2) as defined in IEC 62305-4:2010 section 4.3. At each zone boundary an SPD of the correct type should be installed. This is indicated in Figure 0.2. For example, the Hukseflux SPD01 is a type 2 SPD which is used on the zone boundary from LPZ0b to LPZ2.

Ordering and checking at delivery

Ordering SPD01

SPD01 comes with 5 locking pins. The standard configuration of SPD01 is without cables and mounting options.
Table 1.1.1 Ordering codes for SPD01.

VERSIONS OF SPD01 (part numbers)

SPD01| Surge protection
SPD01-SMF01| Surge protection with tube mount option
OPTIONAL CABLES FOR SPD01|
 | all cables with M12-A female connector on one end, and on the opposite end cable terminated with a removed sheath over 0.15 m; stranded copper conductors with plastic

insulators, stripped ends with ferrules.

‘-03’ after SPD01 part number| standard cable length: 3 m
‘-05’ after SPD01 part number| cable length: 5 m
‘-10’ after SPD01 part number| cable length: 10 m
‘-20’ after SPD01 part number| cable length: 20 m *

*for use on the unprotected side of SPD01. Do not use it to connect instruments to SPD01.

Included items

Arriving at the customer, the delivery should include:

• SPD01
• 5 x locking pin for cable gland (inserted by the factory)
• any other options as ordered

Specifications of SPD01

General overview

SPD01 is a surge protection device intended for use with Hukseflux industrial pyranometers. When properly installed, SPD01 can be used to increase the EN- IEC 61000-4-5:2014+A1:2017 surge immunity to level 4.

Rated operating conditions

RATED OPERATING CONDITIONS|
---|---
Ingress Protection| IP66
Rated operating DC input voltage range| ± 30 V
Maximum DC input current| 5 A
Total DC output current| 5 A
Required over-current protection on power supply line| fast-blow fuse

appropriate current rating for the fuse must be determined from the type and number of instruments connected, but must always be ≤ 5 A

temperature range| -40 to +80 °C

Electrical specifications

SPD01 SPECIFICATIONS|
---|---
**EMC & SURGE IMMUNITY*|
SPD Type| Type 2 SPD
Surge Immunity| IEC 61000-4-5, Level 4 test level 4 kV
Maximum line-to-line surge| 2 kV, 1 kA
Maximum line-to-ground surge**| 4 kV, 2 kA
Common mode signal voltage range| ± 12 V
Differential mode signal voltage range| ± 12 V
Maximum line-to-earth voltage| 12V
Number of protected instruments| Up to 3

• tested with all Hukseflux Industrial pyranometers

** all lines tested as DC power lines

Weight and dimensions

SPD01 MECHANICAL SPECIFICATIONS

Housing material| ASA/PC UL94 V0-1.5mm
Cable glands| M12 (protected)
Cable diameter| 3 to 6 mm
Optional SMF01: rated pole mount

diameter

| 40 to 60 mm
Weight| 0.7 kg

Figure 2.4.1 Overview of SPD01:

• pressure relief vent
• cable gland
• earthing terminal
• gland locking pin

Figure 2.4.2 Dimensions o f SPD01 in x 10-3 m.

Optional accessories

The table provides an overview of accessories that are compatible with SPD01.

OPTIONAL ACCESSORIES

Mounting|
SMF01| SPD01 mounting fixture, for pole/tube mount
PID01| Pyranometer insulation disk

SMF01

SMF01 is a practical metal bracket that helps mounting a surge protection device SPD01 on a vertical mast. It comes with mounting screws and two tube clamps (40-60 mm).

• tube mounting bracket, with mounting screws
• 2 x tube clamp 40-60 mm

Figure 2.5.1.1 Optional tube mounting bracket for SPD01.

PID01, electrical isolation

Hukseflux industrial pyranometers may be safely installed directly onto a PV array. The electrical potential of the array support structure may be affected by, for example fault currents and lightning strikes. Therefore special care should be taken to potential differences that may be present in different parts of the PV plant installation. When installing industrial pyranometers on the PV array structure they should be electrically isolated from the PV array structure. This can be realised using the Pyranometer Isolation Disk (PID01). Earthing of the pyranometer body is still realised through the earthing terminal and is connected to protective earth and to the earthing terminal of the used SPD. This allows pyranometer installation onto the PV array without detailed knowledge of the PV plant grounding structure.

Figure 2.5.2.1 SR300-D1 with PID01 to be used for on-array installation.

Installation of SPD01

Wiring Diagram

SPD01 can be used to protect up to three digital pyranometers and provides a terminal to extend the databus. Five cable glands provide access to the internal screw terminals.
The two unprotected screw terminals (and cable glands) are used to connect long
(> 3 m) cables. This usually means that one terminal is used for the incoming databus and one is used to extend the databus. The terminal block also provides the possibility to end the databus with a termination resistor.
The three protected outputs are meant to connect to short (< 3 m) cables that connect to digital instruments.

Figure 3.1.1 Wiring Diagram of SPD01.

Unprotected inputs (line)

The unprotected lines (positioned on the left) are used to connect and extend the databus. All connected lines to these ports are not protected by the SPD01. In- and outgoing wires use the same clamps. There are two cable glands available that can be used to create a linear data bus by daisy chaining devices.

Protected outputs (device)

The three protected lines (positioned on the right) are protected ports.

Gland co nnections

SPD01 is made out of a plastic enclosure with metal cable glands. The metal cable glands are part of the electrical structure of the SPD01 and form an electrical connection between the cable shield and earth ground. The cable shield should be connected to the cable gland housing. See 4.2 for instructions.
Each cable gland is provided with a locking pin, the locking pin is used to close the gland for weather intrusion when no cable is inserted.

Earth ground

An earthing terminal is located at the side of the enclosure. The terminal should always be connected to protective earth (PE).

Hukseflux industrial pyranometers and SPD01 both feature an earthing terminal. This terminal is marked with an earth ground symbol (), see Figures 3.3.1 and 3.3.2. Both earthing terminals, of instrument and SPD, should be connected to protective earth and equipotential bonding should be realised between the earthing terminals of the instruments and SPD01. Equipotential bonding is required to mitigate any significant current flow through the instrument cable shield which. If not mitigated, such currents may cause the instruments to function unreliably (loss of data) and eventually cause damage. Hukseflux industrial pyranometers and SPD01 should be connected to the same earth potential and the resistance between these two connections points should be minimised. The resistance between the earthing terminal of the instrument and the SPD01 should not exceed 1 Ω. Proper earthing can only be realised through the earthing terminal. The pyranometer feet or mounting screw holes should not be used for earthing the instrument body.

Figure 3.3.2: Hukseflux industrial pyranometers and SPD01 earthing termina.l

WARNING

Connect the earthing terminal to earth ground to guarantee personal safety

Earthing of exposed metal parts of an electrical installation is required by many local safety regulations to ensure that the installation is safe to work on for supporting personnel.
When Hukseflux industrial pyranometers and SPD01 are directly connected to a SCADA system the earthing terminal of the pyranometer and SPD01 should be connected to earth as well as the SCADA system enclosure earth ground to realise equipotential bonding.

Installation of optional mounts

**** SPD mounting fixture, SMF01

The optional mounting fixture, for simplified mounting of SPD01 on a pole or tube, is easy to use. It can be fitted to SPD01 using the mount’s M4 bolts and a 4 mm hex key. The SMF01 with SPD01 can be clamped on a (40 to 60 mm diameter) tube or pole with the included tube clamps using a flat head screwdriver or a 7 mm hex nut driver.

Figure 3.4.1: SPD01 with SMF01.

Electrical inst allation design

Reliable operation of Hukseflux industrial pyranometers is only guaranteed when the electrical installation is done according to the guidelines provided here. Especially the immunity to surges is dependent on the quality of the cabling, earth grounding and equipotential bonding to external protection devices. In addition, it is strongly recommended to perform a lightning risk assessment to make sure that lightning protection measures are properly balanced to the local risk of damage by lightning.

_ Cabling and surge _protection

An optional cable of 3 meters long (10 ft) is supplied with the instrument. This cable is used to connect the instrument either via SPD01 surge protection device to a Supervisory Control and Data Acquisition (SCADA) system or directly to a SCADA system when appropriate overvoltage and surge protection measures are in place. See figure 3.5.1.1. When designing a system for outdoor use in industrial environments take note of the following points:

• Do not use a cable longer than 3 meters to connect a Hukseflux industrial pyranometer to SPD01 or a SCADA system, see the section on rated operating
• In case longer cables are required, extend the cable via a surge protection
• SPD01 can be used to protect up to 3
• Alternatively, another SPD with appropriate specifications can be used to protect the
• The length of each cable connecting an instrument to SPD01 should be kept as short as possible and should never exceed 3 meters (10 ft).

Cabling from SPD01 to the SCADA system can be extended to an arbitrary length not exceeding the maximum length allowed for RS-485 systems, see Figure 3.5.1.2. In practice 100 meters (328 ft) is an economical, safe, and reliable maximum to work with. When extending cables the following must be considered:

• The conductor cross-section or wire gauge (AWG) of the power wires, the corresponding electrical resistance of those wires and the resulting voltage drop. Ensure that the voltage at the location of the instrument never drops below the minimum operating voltage taking the worst-case situation with the maximum in-rush current for each device attached to the power wires.
• Noise pick-up by long signal cables may give rise to communication To reduce this effect, use well-shielded cables with twisted wire pairs.
• Cables must be suitable for permanent outdoor

To reduce the risk of fire and secondary damage to the instrument, SPD01 or power supply, a fast-blow fuse should be installed on the power supply. Multiply the current rating of the fuse by the advised rating by the number of pyranometers attached to the power supply. In case of a failure, SPD01 is designed to cause an electrical short between VDC[+] and VDC[-]. This is to protect the pyranometers in case the SPD01 fails to perform its function.

Figure 3.5.1.2 Example of multi-drop installation.

CAUTION

__

To reduce risk of fire damage a fast-blow fuse must be installed on the power supply. In case of a failure, SPD01 is designed to cause an electrical short between VDC[+] and VDC[-].

The pyranometer cable shield should be connected to earth ground on both sides to meet the EMC specifications and surge immunity as listed in the tables in section 3.4. On the pyranometer-end the cable shield is connected to the instrument body and is connected to earth by connecting the instrument body to the earth using the earthing terminal, see next section. The cable shield between SPD01 and the SCADA system may or may not be connected, depending on the grounding strategy and the general installation design.

Earth connection

For safe and reliable use of industrial pyranometers the earthing terminal is used to connect the instrument body to earth ground. The conductive instrument body is in turn connected to the connector body which provides an earth connection for the cable shield.

Connection of cable shields at the SPD

Cable shields must be connected using the contact spring inside the cable gland. The cable sheat must be removed over the width of the contact spring to make the electrical connection between the cable shield and the contact spring. Internally, in the SPD01 housing, the cable shields are electrically connected to the earthing terminal. Consult the appendix for more information how to connect cable shields.

Appendices

Cable gland installation

EU declaration of conformity

We,  Hukseflux Thermal Sensors B.V., Delftechpark 31, 2628 XJ, Delft,
The Netherlands hereby declare under our sole responsibility that:
Product models                     SPD01
Product type                         Accessory conform with the following directive(s):
2011/65/EU, EU 2015/863       The Restriction of Hazardous Substances Directive
This conformity is declared using the relevant sections and requirements of the following standards,
Hazardous substances            EU RoHS2 (2011/65/EU) and

EU 2015/863 amendment known as RoHS3Eric HOEKSEMA

Director
Delft, 22 May 2024

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