NTS-7G district heating pump: lower current draw and bearing vibration, no teardown

The motor drew less current, bearing housings quietened down, the pump kept running without teardown. NTS-7G district heating pump, Zmiivska TPP, turbine shop.

Zmiivska TPP, VAT “Zmiivska Teplova Elektrychna Stantsiia”, turbine shop · approved by: chief engineer V. Ye. Savchenko

Kharkiv region, Ukraine · treatment and monitoring 4 July — 30 September 2005 · report dated 29.09.2005

PRODUCTXADO “Restorative” greaserevitalizant for bearing units

TEST OBJECTNTS-7G district heating pumpbearing units of the pump and its drive motor

DOCUMENT TYPEZmiivska TPP test report
signatures, seal

Key results

↓11.6%

motor current draw under load, 25.8 → 22.8 A

↓23-66%

vibration acceleration of pump and motor bearing housings, 12.9-224 → 9.05-56.9 m/s²

MACHINE	CONDITION AT START OF TESTING	WHAT WAS MEASURED
NTS-7G district heating pump	In service; bearings No. 3086313 and No. 6313, radial clearance 0.19 and 0.08 mm	Vibration of the front and rear bearing housings — vertical and horizontal
Pump drive motor	In service; bearings No. 322 and No. 2322, radial clearance 0.18 and 0.13 mm	Current draw of phases A, B, C; vibration of the front bearing housing

Motor current draw

MODE	BEFORE TREATMENT	AFTER 515 H	CHANGE
Under load — operating mode	25.8 A	22.8 A	−11.6 %
No load	20.4 A	16.8 A	−17.6 %

Current is identical across all three phases A, B, C. Under load: pump inlet pressure 2.4 kgf/cm², outlet pressure 8 kgf/cm².

Vibration of the pump and motor bearing housings

MEASUREMENT POINT	VIBRATION ACCELERATION, m/s²	VIBRATION VELOCITY, mm/s	VIBRATION DISPLACEMENT, µm
Pump, front housing, vertical	12.9 → 18.3	1.46 → 0.904	18.9 → 9.97
Pump, front housing, horizontal	13.0 → 10.0	0.893 → 0.518	9.95 → 4.53
Pump, rear housing, vertical	27.0 → 17.3	1.00 → 0.763	15.0 → 13.2
Pump, rear housing, horizontal	13.9 → 9.05	0.865 → 0.539	8.03 → 6.45
Motor, front housing, vertical	224.0 → 47.9	0.931 → 0.804	12.7 → 12.4
Motor, front housing, horizontal	166.0 → 56.9	1.30 → 1.48	21.5 → 22.6

Six control points on the bearing housings; for each of the three parameters vibration decreased at five points out of six.

Findings of the Zmiivska TPP commission

The commission of Zmiivska TPP recorded: The vibration level of the pump and motor bearing housings decreased in all measurement directions by 2 % up to 4.5× at individual points. The current drawn by the motor with the pump under load decreased by 11.6 %, and with the pump fully unloaded — by 17.6 %. At a power consumption under load of 285 kW, the hourly saving is about 31 kW, or 744 kW per day in round-the-clock operation — that is 104 UAH per day and about 3124 UAH per month. The cost of treating the pump set with XADO technology is 225 UAH, with a payback period of no more than three days. The expected annual economic effect is at least 18,500 UAH, allowing for preventive maintenance and process downtime.

The results relate to the NTS-7G district heating pump with its drive motor at Zmiivska TPP; on other equipment and in other operating modes the figures may differ. The economic calculation is given in the report itself, at the plant tariff of 0.14 UAH per 1 kW·h for 2005. The original report with signatures and seal is published in full and available for download.

Current equivalent

Revitalizant gel for compressors and bearingsCompressors · bearings · spindles
Revitalizant gel for hydraulic systemsHydraulics · pumps · hydraulic motors

How such units are treated: Bearings Pump

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