SPX Cooling Technologies TG MAG15-50, TG MAG185-125, TG MAG58-80, TG MAG23-65 Trouble shooting

3.20 Trouble shooting

Symptom	Cause	Remedy
No flow	Suction lift too high	1	•	Reduce difference between
Pump not priming				pump and suction tank level.
			•	Increase suction pipe diameter.
			•	Reduce length and simplify suction pipe (use as
				few elbows and other fittings as possible).
				Also see section 3.18 Installation.
	Air leak in suction line	2	•	Repair leak.
	Very low viscosity	3	•	Increase pump speed and reduce axial clearance
				(see section 3.21 Maintenance instructions).
	Suction strainer or filter clogged	4	•	Clear suction strainer or filter.
	Pump casing incorrectly installed	5	•	Install pump casing correctly.
	after repair			See section 3.18 Installation.
	Wrong direction of rotation of motor	6	•	For 3-phase drivers change 2 connections.
			•	Change suction and discharge opening.
				(Attention! Check the location of the safety relief
				valve and correct circulation pump insert).
	Magnetic coupling is slipping	7	•	Check/correct assembly of rotor shaft and bear-
				ings and magnetic coupling
			•	Check start-up conditions for the magnetic cou-
				pling in combination with applied electrical motor
				if necessary add fly-wheel or apply soft start.
			•	Check operating parameters against break-away
				torque of the magnetic coupling.
			•	Check if the pump is blocked, remove blockage.
Irregular flow	Liquid level in suction tank falls too low	8	•	Correct liquid supply
			•	Provide a liquid level switch
	Output too high	9	•	Reduce pump speed/or install a smaller pump.
			•	Install by-pass line with check-valve.
	Air sucking	10	•	Repair leak in suction line.
	Cavitation	11	•	Reduce difference between pump and suction
				tank level.
			•	Increase suction pipe diameter.
			•	Reduce length and simplify suction pipe (use as
				few elbows and other fittings as possible).
				Also see chapter 3.18 Installation.
	Liquid vaporises in pump	12	•	Check temperature.
	(e.g. by heating up)		•	Check vapour pressure of liquid.
			•	Reduce pump speed. If necessary install a larger
				pump.
Not enough capacity	Pump speed too low	13	•	Increase pump speed. Attention! Do not exceed
				maximum speed and check NPSHr.
	Air sucking	14	•	Repair leak in suction line.
	Cavitation	15	•	Reduce difference between pump and suction
				tank level.
			•	Increase suction pipe diameter.
			•	Reduce length and simplify suction pipe (use as
				few elbows and other fittings as possible).
				Also see section 3.18 Installation.
	Back pressure too high	16	•	Check discharge pipe.
			•	Increase pipe diameter.
			•	Reduce working pressure.
			•	Check accessories (filter, heat exchanger, etc.).
	Safety relief valve set too low	17	•	Correct pressure setting.
	Viscosity too low	18	•	Increase pump speed. Attention! Do not exceed
				maximum speed and check NPSHr.
			•	If necessary, install a larger pump.
	Axial clearance	19	•	Check axial clearance and correct.
				See section 3.21 Maintenance instructions.
	Gases come free	20	•	Increase pump speed. Attention! Do not exceed
				maximum speed and check NPSHr.
			•	Install a larger pump

A.0500.551 – IM-TGMAG/02.00 EN (02/2008) 41