Common faults and fault elimination of the mobile scissor lift

Working platform cannot lift.

Voltage is too low.

Check the start electrical position. scope range of the fluctuation of voltage 

is ±10%.

Motor doesn’t rotate.

Check motor and circuit

Motor rotates reverse

Change any two of three phases.

Motor lack s of phase( Motor doesn’t rotate but with buzz).

Check breaker and motor wiring

Lowering valve opens.

Under loosening condition of lowing button, check whether there is electricity in lowing valve or not. If there is electricity in lowing valve, check circuit and eliminate fault; If there is no electricity in lowing valve, either check lowing valve to eliminate fault or replace lowing valve. Slide valve of lowing valve must be kept clean and can move flexibly.

The pressure of overflow valve is adjusted too low.

Adjust again overflow valve at  110% times of rated load.                                                                                                                                        

The oil level is too low and oil pump is absorbed empty.

Add hydraulic oil.

Oil-absorbing strainer  is blocked.

Clean strainer.

Oil-absorbing segment leaks air.

Check oil-absorbing pipes and joints. Tighten joints and replace them if necessary.

Overload happens.

Reduce load and forbid overloading use.

One-way valve leaks oil.

Check one-way valve. If dirt is found in sealing surface of one-way valve, clean one-way valve.

Lowering valve is not sealed enough.

Check whether there is electricity in lowing valve or not with voltmeter. If there is electricity in lowing valve, check circuit and eliminate fault; If  there is no electricity in lowing valve, either check lowing valve to eliminate fault or replace lowing valve. Slide valve of lowing valve must be kept clean and can move flexibly.

Oil cylinder leaks inside.

Replace sealing components of hydraulic cylinder.

Lowering valve is out of order

After pressing lowing button, check whether there is electricity in lowing valve or not. If there is electricity in lowing valve, either check circuit and eliminate fault( At dusty places, dismantle coil 

and clean it; otherwise dust may cause magnetic valve to lose control), or replace lowing valve. Slide valve of lowing valve must be kept clean and can move flexibly.

Lowing- speed control valve is out of adjustment.

Adjust lowing-speed control valve. If adjustment is ineffective, replace it.