Me kana da shawarar da za a iya ɗauka da sauyin ƙaramin kasa na gida? Duk da haka bayan da za a iya ɗauka da sauyin ƙaramin kasa na gida?
Salamu alaykum daga cikin James, na yi aiki da current transformers (CTs) na 10 shekaru.
Daga lokacin da na kai zuwa wurare da mallakin kan, da amfani da kablolar da kuma tattaunawa abubuwan gagarada, zuwa yanzu don nuna aiki a wurare da kula da duk fannoni masu sahinta CT — na yi aiki da manyan outdoor current transformers a shekaru. Kuma ina iya cewa, na yi matsaloli, na bar da su, kuma na samu wani ilimi mai tsarki a baya.
Ya kamata, ya zo wanda shi ne minkali:
“James, za a sanar da batch ta outdoor CTs sannan — akwai wani abu da muna duba?”
Wannan ita ce tambayar mai ma'ana! Saboda haka, na zan bayar ku a yau:
Me ke abubuwa masu muhimmanci a nan da muke so a zama da kula da kusan sanar da current transformers?
Babu kalmomin ingantaccen ilimi — kawai magana mai ma'ana kamar hakan da na samu a shekaru 10. Zan iya taimakawa!
1. Sanar - Ba Da Sune Sune, Duba Wadannan Abubuwa Kafin Yawanci
1.1 Fahimta Parametere na Ingantaccen System
Wannan shine ɗaya — da kuma mafi muhimmanci:
Me ke rated primary current?
Me ke system voltage level? Kamar 10kV, 35kV, ko 110kV?
Shi ne don measurement, metering, ko protection?
Fannoni daɗi suna haɗa da classes da takaitaccen accuracy da requirements. Misali:
Metering CTs suna buƙatar precise (yanayi 0.2S ko 0.5S);
Protection CTs suna haɗa da performance a lokacin faults (kamar 5P20 ko 10P20).
1.2 Environmental Conditions Matter Big Time
Outdoor CTs suna da ƙarin wind, rain, snow, sun, da ƙarin temperature extremes.
Akwai salt spray corrosion? Mafi yawan darasi ko chemical plants;
Akwai ƙarin temperature swings? Kamar -30°C a shekarun yamma da +40°C a ranar rana;
Akwai vibration ko lightning risk? Wadannan suna haɗa da lifespan da kuma reliability.
Saboda haka, a zama da model, za ka:
Corrosion-resistant housing (stainless steel ko fiberglass);
UV and aging-resistant insulation materials;
At least IP55 protection rating to block dust and water.
1.3 Pick the Right Structure Type
Common outdoor CT types include:
Bushing type – often used at transformer outlets;
Core-type (window-type) – common on overhead lines;
Post-type – used near GIS or circuit breakers.
Choosing the wrong type can lead to installation difficulties or even measurement inaccuracies and safety risks.
2. Installation — Small Steps, Big Impact
2.1 Grounding Is Non-Negotiable
The secondary side of a CT must be grounded properly — otherwise, an open circuit can create dangerously high voltages, risking both life and equipment.
In outdoor conditions with high humidity and frequent rain, poor grounding can cause:
Insulation degradation;
False trips;
Equipment damage.
So always:
Check that ground connections are tight and solid;
Test the grounding resistance;
Use anti-corrosion measures so the connection stays good over time.
2.2 Double-Check the Polarity
This is an old issue, but still a big one. Getting polarity wrong can cause:
Incorrect measurements;
Metering errors;
Protection misoperations — like tripping when it shouldn’t.
Especially in differential protection schemes, a reversed CT polarity can create abnormal differential currents and false trips.
Before installation:
Make sure P1, P2, S1, S2 markings are clear;
Confirm secondary wiring matches;
Perform a polarity test if unsure.
2.3 Seal It Up and Keep Water Out
Even though outdoor CTs have weatherproof ratings, improper installation can still let moisture in.
If not sealed well:
Internal insulation drops;
Terminals corrode;
Measurement becomes unreliable.
After installation, check:
All covers are tightly fastened;
Sealing gaskets are intact;
Cable entries are properly sealed against water.
2.4 Avoid Mechanical Stress
Some installers force the CT into place by pulling or twisting — this can deform internal parts and damage the unit.
Instead:
Use proper mounting brackets;
Adjust alignment before connecting;
Never use brute force to make things fit.
2.5 Testing After Installation Is a Must
Just because it’s installed doesn’t mean it’s done. You should still do:
Ratio test – confirm actual ratio matches nameplate;
Polarity test – double-check wiring direction;
Excitation characteristic test – especially for protection-grade CTs;
Insulation resistance test – ensure good insulation;
Load simulation test – run a quick check before full operation.
3.Final Thoughts
As someone who’s spent 10 years in the field, here’s what I’ve learned:
“Wrong selection means wasted effort; bad installation means hidden dangers.”
Whether you're new or experienced, when dealing with outdoor current transformers, you must treat every step with care and respect.
If you're just starting out, ask for help, read the manuals, and learn from those who’ve done it before. If you're seasoned, don’t get complacent — after all, safety comes first, and accurate data directly affects grid stability and cost control.
If you ever run into issues during selection or installation, feel free to reach out. I’m happy to share more hands-on experience and practical tips.
Here’s hoping every outdoor current transformer runs safely and accurately, protecting the power grid day and night!
— James
