Wuhan Huazhong Numerical Control HNC-18M, Operator'S Manual, Page: 5 / 119

I
Precautions
This section enumerates safety precautions for protecting the user
and preventing damage to the machine. Read the contents of this
part thoroughly before attempting to use the machine.
1. The working temperature for the Numerical Control (NC) unit
and its cable cabinet is 0 to 45°C (32°F to 113°F). No freezing is
allowed. The temperature variation should be less than 1.1°C/min
(2°F/min). Humidity should be kept below 90% Relative Humidity,
non-condensing and without frost; 75% Relative Humidity or lower is
more desirable.
2. For storage, the temperature range should be kept within
–20°C to 60°C (-4°F to 140°F) non-condensing and without frost.
All devices should be placed indoors and away from sunshine, dust,
eroding gases and moisture.
3. Impact during transportation or other situations should be less
than 5.9 m/s (0.6 g) for vibrations in the range between 10 to 60 Hz.
4. Correct grounding is critical for the NC unit and other electrical
devices. No grounding or incorrect grounding may injure the
operator or damage components of the NC devices. If the devices
are not correctly grounded, inductive interference from electric
motors and appliances can give errors and unexpected results.
5. Filters are used on cooling fans to prevent dust from entering
into devices. However, after time filters become clogged, preventing
adequate cooling. Clean the filters every three months. In dusty
environments such as wood routers, clean the filters more often.
6. After a long period of non-operation, NC devices should be
cleaned and dried. Also check the wiring and ground connections.
Once power is resumed after non-operation, observe the operation
for several hours to make sure there is no unexpected behavior.
7. Never machine a workpiece without first checking the