Fluke 1535 Tester de rezistență la izolație

Model positioning: Basic digital megohmmeter with 250-2500 V test voltage; no data storage or USB communication. The higher-end model 1537 features data storage, USB communication, fine-tunable test voltage, ramp test, and AC/DC voltage measurement.

Specificații electrice de bază

Articol	Fluke 1535
Test Voltage Ranges	250 V / 500 V / 1000 V / 2500 V (fixed ranges, no 100‑V‑step fine adjustment)
Insulation Resistance Range	200 kΩ ~ 500 GΩ
Short‑circuit Current	＞2 mA (＞5 mA for 1537)
Automatic Calculation	Polarization Index (PI), Dielectric Absorption Ratio (DAR); No Dielectric Discharge (DD), no Ramp test
Leakage Current Measurement	1 nA‑2 mA; Capacitance Measurement: 0.01‑2 μF
Evaluare de siguranță	CAT IV 600 V, IEC 61557‑5, Gradul de poluare 2
Live‑circuit Alarm	High‑voltage alarm triggered above 30 V; auto‑discharge and residual‑voltage display upon test completion
Alimentare electrică	8 × AA (LR6) alkaline batteries; ≥1300 tests at 2500 V; ≥6500 tests at 250 V
Dimensiuni / Greutate	211 × 93 × 184 mm, 1.3 kg
Interval de temperatură	Funcționează: ‑10℃ ~ +50℃; Depozitare: ‑20℃ ~ +60℃; Non‑condensing; Altitude ≤2000 m
Protecție la intrare	IP40; Backlit LCD; No internal storage, No USB port

Comparație de modele: 1535 vs 1537

Funcţie	1535	1537
Fixed voltage ranges: 250/500/1000/2500 V	✅	✅
250‑2500 V fine adjustment in 100 V steps	❌	✅
Automatic PI / DAR calculation	✅	✅
Dielectric Discharge (DD), Ramp voltage test	❌	✅
ACV / DCV and general resistance measurement	❌	✅
Stocarea datelor, tagging, USB upload to PC	❌	✅
Short‑circuit current	＞2 mA	＞5 mA

Standard Packaging List

Standard Deliverables:

Fluke 1535 Unitatea principală
3-colour test leads (roşu, negru, verde) with alligator clips
Red-black test probes
Soft carrying case
User manual & quick-start guide

❗ Not included: USB cable, software pentru PC, hard-shell tool case (comanda separat); 8-AA batteries to be provided by user.

Aplicații tipice
Insulation testing for motor & generator windings (low-voltage and medium-voltage motor pre-testing)
Insulation preventive testing for transformers, cables and busbars
Insulation test for DC side of PV arrays (2500 V range suitable for photovoltaic strings)
On-site electrical maintenance, fault troubleshooting, pre-/post-overhaul insulation evaluation
Plant equipment spot-check; handheld on-site use for scenarios without report-generation requirements

👉 Upgrade to Fluke 1537 if you need data logging, report export, ramp withstand test or fine voltage adjustment.

Capcanele de selecție & Hard-rule Warnings
1535 has no storage and cannot export reports via PC. PI / DAR values must be manually recorded on-site; do not expect CSV export after purchase.
Short-circuit current is only ＞2 mA. For large-capacity long-length cables, charging time is longer and readings stabilize slower compared with the 1537 (5 mA).
Never perform insulation tests on live circuits. The instrument triggers alarm above 30 V, but full power-off and adequate discharge of the unit-under-test are mandatory.
Condensul este interzis. Measurement distortion occurs under high-humidity conditions with dew formation.
Derate operation above 2000 m altitude; full-range 2500 V testing is not recommended.
Always wait for automatic discharge completion and verify zero residual voltage before disconnecting test leads.
Compatible Alternatives

Upgrade de aceeași marcă: Fluke 1537 (identical form factor, adds storage, USB and ramp test)

Equivalent competitors: Megger MIT2500; HIOKI IR3455-30

Comparație completă: Fluke 1535 vs Fluke 1537 Tester de rezistență la izolație

These two models share identical enclosure, dimensiuni, weight and base measuring range. Key differences lie in short-circuit current, voltage tuning, advanced test functions, data-logging communication and additional multimeter features.

Element de comparație	Fluke 1535	Fluke 1537
Fixed test voltage ranges	250 V / 500 V / 1000 V / 2500 V	250 V / 500 V / 1000 V / 2500 V
Fine‑step adjustable voltage	❌ Only four fixed ranges, no fine‑tuning	✅ 250‑2500 V adjustable in 100 V increments
Insulation resistance measuring range	200 kΩ‑500 GΩ	200 kΩ‑500 GΩ
Short‑circuit current	＞2 mA	＞5 mA (faster charging & stabilized readings for large‑capacity cables)
Polarization Index (PI) / Dielectric Absorption Ratio (DAR)	✅ Auto‑calculated	✅ Auto‑calculated
Dielectric Discharge (DD)	❌ Not supported	✅ Supported
Ramp withstand‑voltage test	❌ Not supported	✅ 100 V/s linear ramp with breakdown‑voltage indication
ACV / DCV and general resistance measurement	❌ No multimeter function	✅ Measures AC/DC voltage & general resistance
Stocarea datelor & tagging	❌ Real‑time reading only	✅ Storage, tagging & scheduled‑test recording
USB interface & PC report‑export software	❌ No USB port, no export capability	✅ Mini‑USB, report generation with bundled PC software
Leakage current / Capacitance measurement	✅ 1 nA‑2 mA; 0.01‑2 μF	✅ 1 nA‑2 mA; 0.01‑2 μF
Safety rating	CAT IV 600 V	CAT IV 600 V
Putere / Greutate / Mechanical design	8 × AA batteries; 1.3 kg; IP40	8 × AA batteries; 1.3 kg; IP40

Key Difference Explanations

Short-circuit current (easily overlooked parameter)

The 1537 delivers ＞5 mA short-circuit current: for long cables and large-capacitance motor windings, charging completes rapidly without long waiting for stable readings.

The 1535 provides only ＞2 mA. Long stabilization time is required for high-capacitance test objects; it suits small-to-medium motors and short cables.

Exclusive Ramp test for 1537

Performs withstand-voltage scanning with gradual voltage rise to pinpoint insulation weak points. Widely used in motor overhaul, high-voltage pre-test and incoming-product inspection. The 1535 outputs fixed high voltage only and cannot execute gradual-ramp tests.

Înregistrarea datelor & report output

Fluke 1535: No onboard storage; all readings must be manually transcribed. Suitable for spot-checks, fault-finding and work without formal reporting requirements.

Fluke 1537: Stores multiple test sets, exports data via PC and generates reports. Ideal for third-party inspection, power-industry preventive testing, PV site acceptance and archive-oriented workflows.

Built-in AC/DC voltage measurement

The 1537 integrates basic multimeter functions to verify residual voltage on-site without carrying an extra multimeter, improving convenience in substation work.

Selection Guidance

✅ Choose Fluke 1535:

Routine plant spot-check and fault diagnosis

Small-to-medium motors and short-length cables

No data-storage or formal-report requirement, manual paper-based logging

Budget-constrained projects

✅ Choose Fluke 1537:

Formal test-report generation and data archiving

Test objects include long-distance power cables, large-capacity motors and large transformers

Advanced insulation diagnostics: Ramp test & Dielectric Discharge for aged-insulation assessment

Non-standard test-voltage requirements (de ex. 1700 V, 2100 V)

All-in-one instrument for insulation test plus on-site voltage measurement

Packaging Differences

Fluke 1537: Main unit, test leads & probes, soft case; USB cable and PC software CD included. Hard-shell tool case sold separately.

Both models require user-supplied 8-AA batteries.

Hard-rule Notes

Both instruments require fully power-off test objects. The 30-V live-circuit alarm serves as a reminder and cannot replace formal power-cut & voltage-verification procedures.
Avoid applying the 1535 to ultra-capacitive long cables: long charging cycles and reading drift may occur.
The 1537 stores data locally without onboard printing; reports must be generated after importing datasets to PC software.

Fluke 1535 vs 1537｜Selection Conclusion for Power-industry Applications

For power-sector applications (preventive testing, substații, distribution networks, third-party accredited testing agencies), select the Fluke 1537 implicit. The 1535 is only acceptable for simple fault-finding without formal data archiving.

Power-field Comparison (aligned with DL/T preventive-test specifications)

Power‑sector Requirement	Fluke 1535	Fluke 1537	Practical Impact for Field Work
Short‑circuit current	＞2 mA	＞5 mA	For long cables, large transformers and generator windings (high‑capacitance DUTs), 1537 achieves fast charging and stable readings and cuts waiting time. 1535 exhibits slow charging and reading drift on high‑capacitance equipment.
Stocarea datelor + USB export	❌ No storage, only on‑site reading	✅ Onboard storage, PC export	Preventive testing and condition‑based maintenance demand traceable raw datasets, formal reports and equipment‑insulation archives. The 1535 only supports manual paper logging without traceability.
100‑V‑step adjustable voltage	❌ Four fixed ranges only	✅ 250‑2500 V step tuning	Enables non‑standard test voltages for diagnosis of legacy / aged equipment.
Dielectric Discharge (DD) & Ramp test	❌ Not supported	✅ Supported	Ramp scanning detects latent insulation defects and prevents equipment damage from direct full‑voltage stress. DD quantifies ageing of old insulation systems.
Native AC/DC voltage measurement	❌ Absent	✅ Available	Residual‑voltage verification directly on the tester; eliminates the need for an extra multimeter at substations.
PI / DAR automatic calculation	✅ Supported	✅ Supported	Both comply with PI/DAR test requirements for transformers, motors and cables specified in DL/T474.1‑2018.

Scenario-based Recommendations

✅ Mandatory selection: Fluke 1537 (Most power-industry scenarios)

Power-utility substation maintenance, distribution-network preventive testing and equipment condition evaluation
Accredited third-party power-testing services requiring formal traceable test reports
Test subjects include long-distance power cables, high-capacity distribution transformers and generators / motoare mari
Advanced insulation diagnostics: ramp-voltage scanning and Dielectric Discharge assessment for aged insulation
Digital-operation workflows with PC-imported datasets linked to equipment asset ledgers

For high-capacitance test items in power preventive tests, 5 mA short-circuit current is a critical performance index. The 2 mA output of the 1537 results in prolonged unstable readings for long-length cables and reduces field efficiency.

✅ Acceptable selection: Fluke 1535 (Limited scenarios only)

Distribution-network emergency repair and on-site fault troubleshooting without formal preventive-test reporting or long-term archiving
Test objects are small-capacity equipment and short cables with low capacitance
Budget constraints, qualitative insulation judgement only; all PI/DAR values manually logged on paper.

Critical Selection Warnings

The Fluke 1535 cannot export data. Not recommended for accredited third-party testing or acceptance projects where report traceability is mandatory.
Maximum test voltage for both instruments is 2500 V. Neither can perform 5000-V insulation tests for ≥10 kV main transformers. Select Fluke 1555 / 1550C for 5-kV-range requirements.
Both units feature CAT IV 600 V safety rating, auto-discharge and residual-voltage indication with identical safety performance.

Sfaturi pentru achiziții

Standard power-team configuration: Primary tester = Fluke 1537. Supplement with a small quantity of 1535 units for emergency-repair crews for fast fault diagnosis.

Hard-shell carrying cases and extended-length test-lead kits are not standard accessories for the 1537. These are strongly recommended for power-site deployment.