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Summary of Contents for Raychem nvent KMV(2)
- Page 1 Installation, Maintenance and Operation Manual MINERAL INSULATED (MI) SERIES HEATING SYSTEMS...
- Page 2 TABLE OF CONTENTS 1 – General information ����������������������������������������������� 4 2 – Heating cable selection and storage �����������������������7 3 – Heating cable installation �������������������������������������� 9 4 – Components selection and installation ���������������� 23 5 – Temperature control and limitation ���������������������� 24 6 –...
- Page 3 Typical configuration for MI-heating cable system (single conductor) Junction box Circuit identification tag MI cold lead cable (single conductor) Hot/cold joint Loop of MI heating cable (single conductor) Typical configuration for MI-heating cable system (dual conductor) Junction box Circuit identification tag MI cold lead cable (dual conductor) Hot/cold joint Dual conductor...
- Page 4 1 – GENERAL INFORMATION Use of the manual This Installation and Maintenance manual applies to nVent RAYCHEM Mineral Insulated (MI) series resistance heating cable systems installed on thermally insulated pipes and vessels and associated equipment. In particular it refers to mineral insulated (MI) series...
- Page 5 Design type D Dual conductor Cold lead cable (standard 2 m) Gland Hot/cold joint End cap Potted seal 300 mm Heating cable length Flexible tail length Design type E Dual conductor Cold lead cable (standard 2 m) Hot/cold joint Gland Potted seal 300 mm Heating cable length...
- Page 6 Area Classification – Ordinary FMV/KMV/FMIN/KMIN/HCC/HCH/ HDC/HDF/HSQ/ HAx/HIQ Area Classification – Hazardous, Zone 1 or Zone 2 Special conditions for safe use in hazardous area: Please refer to relevant hazardous area certifications Certificate No. Code Nos. FMV/FMIN/HCC/HCH/HDC/HDF/HSQ/HAx/HIQ (heating elements) Baseefa 02ATEX0046X II 2 G EEx e II T6 to T1 HCC/HCH/ HDC/HDF/HSQ/HAx/HIQ (bulk cable) Baseefa 02ATEX0045U...
- Page 7 2 – HEATING CABLE SELECTION AND STORAGE The selection of the proper heating cable and components, best suited for the application must be checked against the relevant product literature, the most important product properties are summarized in following table: Table 1: Properties of MI heating units MI Heating Cable Type HCC/ HCH HDC/ HDF...
- Page 8 Ensure that the heating cable voltage and temperature rating is suitable for the application. Changing design parameters such as voltage or cable length will result in a different power output and maximum sheath temperature� This may require a redesign of the entire system� To prevent fire or explosion in hazardous areas, verify that the maximum sheath temperature of the heating cable is below T-class or auto-ignition temperature...
- Page 9 3 – HEATING CABLE INSTALLATION Warning As with any electrical equipment or wiring installation that operates at line voltages, damage to heating cable and components, or incorrect installation that allows the penetration of moisture or contamination can lead to electrical tracking, arcing and potential fire hazard�...
- Page 10 W alkthesystemandplantheroutingoftheheating cable on the pipe, including tracing of heat sinks. e.g. valves, flanges, supports, drains etc. I nspectpipingforburrs,roughsurfaces,sharp edges etc. which could damage the heating cable. Smooth off or cover with layers of aluminium foil. At elevated sheath temperatures consider the use of stainless steel foil.
- Page 11 Figure 4 : Minimum bending radius of MI heating cables 6 x ∅ Cable ∅ > 6 mm D onotrepeatedlybendandstraightenthecable. K eepheatingcablestrunglooselybutcloseto the pipe being traced, to avoid interference with supports and other equipment. A ddadditionalheatingcabletotracethefittingsand supports as required by the design specification or engineering documents.
- Page 12 Table 2: Typical allowances (in mm) per run of cable Light Light Heavy Heavy Typical Flange Field inch valve valve valve valve pipe pair variance (flanged) (threaded (flanged) (threaded shoe welded) welded) 0.75 20 1060 1220 1220 1520 1520 1060 1830 1060 2140...
- Page 13 3�3 Heating cable attachment Fix in place with metal bandings, tie wire or wire cloth band at a typical interval of 300 mm and additionally where necessary. The use of tie wire with softer sheath MI heating cables (like copper HC and cupro-nickel HD) should be avoided, as the tie wire can damage the heating cable surface over time.
- Page 14 R eadthedesigndocuments,inparticular concerning the need for cable allowances and regard the location of junction boxes/controllers before permanently attaching the cable to the pipe. V erifyifthedesigndocumentationrequiresthatthe heating cables have to be covered by aluminium or stainless steel foil before the insulation is applied. I nstallationontankstypicallyrequiresadditional fixing devices as pre-punched steel strips as shown below:...
- Page 15 3�4 Attachment materials S tainlesssteelpipestrapsfordifferentpipe dimensions up to 36 “ (e.g. PB 300). S tainlesssteelbanding(30 m roll) together with stainless steel buckles (one per fixing) (e.g. SNLS + SNLK). T iewire(e.g.RMI-TW)isespeciallysuitablefor the fixation on irregular shapes like pumps, valves etc..
- Page 16 Figure 10: Attaching hot-cold joint and end cap A ttachhot-coldjointtoendofpipenearestthe power supply point, and the other end of heating cable to the other end of the pipe. Support hot-cold joint by attaching cable with pipe straps/banding Stainless steel pipe strap, banding, at a distance of 6 inches (150 mm) on either side tie wire, wire cloth band, etc.
- Page 17 excess cable by waving along pipe and increasing amount used at each pipe support. N ote:Donotuseupexcesscableatonelocation. Distribute equally along pipe. Figure 13: Completed MI heating cable installation Hot-cold joint Tie wire / wire cloth band Figure 14: Pipe strap spacing Junction box Hot-cold Stainless steel pipe straps, banding,...
- Page 18 Figure 16a: Valves For valve sizes 31/2“ (90 mm) or smaller Stainless steel pipe straps, banding, tie wire or wire cloth band Pipe Valve body Stainless steel pipe straps, banding, tie wire or wire cloth band Pipe Valve body Apply tie wire, wire cloth MI heating cable band or other...
- Page 19 Figure 17: Installation at 90° elbow Steel pipe Stainless steel pipe straps, banding, tie wire or wire cloth band(typical) MI heating cable MI heating cable is applied to outside radius of elbow. Figure 18: Flanges Stainless steel pipe straps, banding, tie wire or wire cloth band Flange Apply tie wire or wire...
- Page 20 Figure 19: Cable layout over clamps and straps Bar hanger Pipe MI heating Stainless steel pipe straps, cable banding, tie wire or wire cloth band Figure 20 : Shoe and sleeve type support See design drawings for specific heating cable length needed. MI heating cable Pipe Stainless steel pipe straps,...
- Page 21 T heminimumspacingmustberespected,unless design documentation clearly states other values, also refer to page 11, figure 5. C heckdrawingsfordummyleginsulation. P umpsshouldhavetheirownheatingcable, separate from the connection box. Figure 22: Pumps Junction box Stainless steel pipe straps, (series connect) banding, tie wire or wire cloth band Pump body...
- Page 22 Figure 23 : Cable applied on metal wire mesh C onsultthedesignspecificationfortheheat-tracing requirements of fittings and supports. T heheatingcable’sminimumbendradiusmustbe respected (refer to Table 1). T heminimumspacingmustberespected,unless design documentation clearly states other values, also refer to page 11, figure 5. 3�6 H eating cable allowances All parts of a heat traced system that increase the surface area of the insulated pipe/ vessel or metallic fins...
- Page 23 4 – COMPONENTS SELECTION AND INSTALLATION 4�1 General notes Use the Design Specification to select required components. nVent components must be used to satisfy Standards and Approval Body requirements and the nVent warranty to apply. 4�2 C omponent installation hints O nhorizontalpipeslocatejunctionboxesbelow pipe where ever possible.
- Page 24 5 – TEMPERATURE CONTROL AND LIMITATION 5�1 General rules nVent MI series heating cables are constant power output heaters and as such typically require temperature control, unless otherwise explicitly specified. Good practice and local regulations may require additionally independent temperature limitation devices;...
- Page 25 T helimitermustbesettoensurethatthemaximum temperature of the surface of the cable does not exceed either T-class or maximum working temperature of the heater for a given output under worse case conditions. W arning As with any temperature measurement equipment, possible falsification of true temperatures due to increased heat loss caused by the sensor itself might lead to inaccurate temperature readings or unsafe tripping of safety limiters�...
- Page 26 5�3 Sensor placement: Temperature limiter device Typically the sensor is being placed on a length of cable, that is separated from the pipe by means of insulating material, in order to create an “artificial hotspot”. The choice of the right location for the limiter sensor depends on, but is not limited to following aspects: F lowdirectionofthefluid,bestlocation:upstream in case of warmer inrushing fluid.
- Page 27 6 – THERMAL INSULATION AND MARKING 6�1 Pre-insulation checks V isuallyinspecttheheatingcableandcomponents for correct installation and possible damage. (See Section 10 if damaged.) I nsulationresistancetesting(asperSection8) is strongly recommended prior to covering the pipe with thermal insulation. D ischargecableimmediatelyafterinsulationtest. 6�2 I nsulation related requirements C orrecttemperaturemaintenancerequiresproperly installed and dry thermal insulation.
- Page 28 suitable heat sink of temperature rated metal foil and wire cloth band may be used to improve heat- transfer. Also refer to design documentation, which may specify this requirement as well as material type, thickness etc... Further details may also be described in local insulation standards.
- Page 29 Figure 24: Typical MI identification tag (for use in hazardous areas) 1180 MI Unit Reference: B/HSQ1M1000/43M/1187/230/2M/SC1H2�5/X/M20/EX Heating Cable Ref.: HSQ1M1000 Element Length: 43 m Year of Manufacture: 2006 Circuit Length (if different): Grade: (high) Design Temperature Class: T1 Zone1 Design Method: Limiter-Lockout Maximum Withstand Temperature: 450°C Max.
- Page 30 3. “ Limiter-Lockout”indicatesthatthedesignmethod used assumes the installation of an approved limiter (typically a safety temperature limiter which sensor is installed on the heating cable surface using an “artificial hotspot”). The set point of the limiter must be below the T-class of the area and may require an additional down-adjustment for potential falsifying of the measured temperature, refer to the instructions given by the manufacturer...
- Page 31 7 – POWER SUPPLY AND ELECTRICAL PROTECTION Do not energize cable when it is coiled or on the reel. 7�1 Earth connection Bond the metal sheath of the heating cable to a suitable earth terminal. 7�2 Electrical loading Size overcurrent protective devices according to the design specification and/or local standard practices.
- Page 32 8 – SYSTEM TESTING WARNING: Fire hazard in hazardous locations� Megger tests can produce sparks� Be sure there are no flammable vapors in the area before performing this test (hot work permit)� 8�1 Testing of insulation resistance and conductor resistance nVent recommends insulation resistance test ...
- Page 33 9 – OPERATION, MAINTENANCE AND REPAIRS WARNING: Heating cables are capable of reaching high temperatures during operation and can cause burns when touched� Avoid contact when cables are powered� Thermally insulate the traced pipe or equipment before energizing the cable� Use only properly trained personnel�...
- Page 34 Temperature maintenance systems should be tested at least twice a year. 9�3 Piping systems repair and maintenance Isolate heating cable circuit and protect the heating cable from mechanical or thermal damage during pipe repair work. Check heating cable installation after pipe repairs and make sure, that thermal insulation is restored, following the recommendations in Section 8.
- Page 35 10 – TROUBLE SHOOTING WARNING: Damage to cables or components can cause sustained electrical arcing or fire� Do not energize heating cables that have been damaged� Damaged heating cable or terminations must only be repaired or replaced by qualified personal� Contact nVent for assistance�...
- Page 36 11 - SYMPTOM AND PROBABLE CAUSES Symptom: Insulation resistance less than expected Probable Causes 1 Rainy or high humidity 2 Nicks or cuts in heating cable sheath, with moisture present 3 Kinked or crushed heating cable. 4 Arcing created by damage to the heating cable. 5 Physical damage to heating cable is causing a direct short.
- Page 37 Corrective actions 1 Dry tails and face of seal Visually inspect cable for damage, especially at elbows, flanges, and around valves. If damaged, repair or replace heating cable. Inspect power connection box for moisture or signs or tracking. Dry out connections and retest. 5 Check for visual indications of damage around the valves, pump, and any area where there may have been mainte-nance work.
- Page 38 Symptom: Power output appears correct but pipe temperature is below design Probable Causes 1 Wet or missing insulation with proper weather- proofing 2 Insufficient heating cable on valves, maintain temperature at flanges, supports, pumps, and other heat sinks 3 Temperature controller set incorrectly 4 Improper thermal design used 5 Temperature sensor in wrong location 6 Low fluid temperature entering pipe...
- Page 39 Corrective actions 1 Remove wet insulation and replace with dry insulation and secure it 2 Confirm compliance with system design. (If valve, flange, and pipe support types and quantities have changed, additional heating cable may be required.) 3 Reset temperature controller 4 Contact your nVent representative to confirm the design and modify as recommended 5 Confirm that sensor is in the correct location...
- Page 42 Fax +370 5 2330084 ntm-sales-tr@nvent.com info.baltic@nvent.com United Kingdom Magyarország Tel. 0800 969 013 Tel. +36 1 253 4617 Fax 0800 968 624 Fax +36 1 253 7618 salesthermalUK@nvent.com saleshu@nvent.com Nederland Tel. 0800 0224978 Fax 0800 0224993 salesnl@nvent.com nVent�com ©2018 nVent. All nVent marks and logos are owned or licensed by nVent Services GmbH or its affiliates. All other trademarks are the property of their respective owners. nVent reserves the right to change specifications without notice. Raychem-IM-DOC1235-EN-1805...
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