Initial Start-Up Procedure; General; Start-Up Procedure - Danfoss T90 Series Service Manual

Service Manual
Series T90 Axial Piston Pumps

Initial start-up procedure

General

Start-up procedure

© Danfoss | March 2020
Follow this procedure when starting-up a new pump installation or when restarting an installation in
which the pump was removed.
W
Warning
Unintended movement of the machine or mechanism may cause injury to the technician or bystanders.
To protect against unintended movement, secure the machine or disable/disconnect the mechanism
while servicing.
Prior to installing the pump, inspect for shipping damage.
1. Ensure that the hydraulic fluid and system components (reservoir, hoses, valves, fittings, and heat
exchanger) are clean and free of contamination.
2. Install new system filter element(s) if necessary. Check that inlet line fittings are properly tightened
and there are no air leaks.
3. Install the pump. Install a 50 bar [1000 psi] gauge in the charge pressure gauge port M
4. Fill the housing by adding filtered fluid in the upper case drain port. Open the case plug in the top of
the control to assist with air bleed.
5. Fill the reservoir with hydraulic fluid of the recommended type and viscosity. Use a 10-micron filler
filter. Fill inlet line from reservoir to pump.
6. Disconnect the pump control input signal.
After start-up the fluid level in the reservoir may drop due to filling of the system components. Check
the level in the reservoir to maintain a full fluid level throughout the start-up procedure.
C
Caution
Damage to hydraulic components may occur from failure to maintain fluid supply.
7. Use a common method to disable the engine to prevent the engine from starting. Crank the starter
for several seconds. Do not to exceed the engine manufacturer's recommendation. Wait 30 seconds
and then crank the engine a second time. This operation helps remove air from the system lines. Refill
the reservoir to recommended full fluid level.
8. When charge pressure reaches 3.5 bar [50 psi], enable and start engine. Let the engine run for a
minimum of 30 seconds at low idle to allow the air to work itself out of the system. Check for leaks at
all line connections and listen for cavitation. Check for proper fluid level in reservoir.
C
Caution
Air entrapment in fluid under high pressure may damage hydraulic components.
Do not run at maximum pressure until system is free of air and fluid has been thoroughly filtered.
9. When adequate charge pressure is established (as shown in model code), increase engine speed to
normal operating rpm to further purge residual air from the system.
10. Shut off the engine. Connect the pump control signal. Start the engine, checking to be certain the
pump remains in neutral. Run the engine at normal operating speed and carefully check for forward
and reverse control operation.
11. Continue to cycle between forward and reverse for at least five minutes to bleed all air and flush
system contaminants out of loop.
Normal charge pressure fluctuation may occur during forward and reverse operation.
12. Check that the reservoir is full. Remove charge pressure gauge. The pump is now ready for operation.
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