Thank you Mr.SteveKW,
Can CRC-Lectra be used for medium voltage (16.5kV) machines?
If any guidelines available from standards like IEC, IEEE etc., for specifications of cleaning solvents for the above application.
Advanced thanks..
Carbon Tetra Chloride will damage most of the insulation systems. Standards like IEC, IEEE, NEMA, etc will never take the responsibility to endorse any service procedure or product.
Development of materials and procedures are the responsibility of business individuals or organizations and normally is kept as a proprietary information.
The suggested product (Lectra Clean) will work fine for almost any winding but test before application is required in order to ensure it does not affect that particular winding.
we use a product called Elecosol 30, manufactured by this company. Its effective and versatile and always gets results. They do make a lot of claims about the product which I have found to be true, but they wont make any guarantees. They claim its suitable for use with HT machines up to 25kv but we dont get involved with machines above 3.3kv so I cant really comment on its suitability for your requirements. I also appreciate its probably not available in your part of the world but there must be similar companies offering similar products. If you are looking for large volumes I would try to find a similar chemical supply company, get their "comission-hungry rep`" down, see what they can offer and hammer out a deal.
The most common and difficult to removed is grease/oil contamination,so I presume this is one of the reason why you asked for cleaning solvent without CTC.In our fleet, we're using LECTRA CLEAN (20 L/can) for cleaning motors which are heavily contaminated by over greasing of open type ball bearings. However..take note that one of the component of this compound is isoprophyl alcohol, where during evaporation it leaves condensation which we know is bad. As corrective measure,immediately after cleaning using this solvent, we usually introduce external heating overnight to ensure that the windings are dry then megger test and spray a light coat of insulating varnish (optional) before assembly.
After cleaning with CRC LECTRA, it may not possible to heat the heavy machine windings (250kw to 5100mW & 290mVA machines). So Is there any other option/solvent available to avoid condensation of Isopropyl alchohol on windings?
Check the IR (insulation resistance) and PI (Polarization Index). If the test figures are below specs,(IEEE Std 43) you shall have to dry or wash and dry the windings.
Amax 378 works well and has a high dialectric. It is more expensive than the products put out by Ecolink in Georgia which also have good electrical properties
We have had good success with cryogenic cleaning - using dry ice. There are no issues with drying out the windings. It meeds a specialist to do it . If interested I can look out some details.
