MRH 175 – Service

June 23, 2025

Crane load indication accuracy

1917.46(a)(1)(ii)

The accuracy of the load indicating device, weight-moment device, or overload protection device shall be such that any indicated load (or limit), including the sum of actual weight hoisted and additional equipment or “add ons” such as slings, sensors, blocks, etc., is within the range between 95 percent (5 percent underload) and 110 percent (10 percent overload) of the actual true total load. Such accuracy shall be required over the range of daily operating variables reasonably anticipated under the conditions of use.

August 13, 2024September 26, 2025

AC not working in cab

Here is the condensed version of the expanded troubleshooting tree.

Issue

AC/Heat unit not working

Cause

The AC unit not working can be caused by multiple problems, follow the procedures in the resolution notes to find out what is wrong with the unit, or if it need replaced

Resolution

Check the circuit breakers that control the AC and heat units
2. Check phase detector inside AC unit to be sure it has 2 lights
3. Replace AC controller to the left of seat
4. Check to see if the Condenser fan on the back of the cab runs when AC is selected, if not, check the fuses
5. Try using the “Defrost” setting and see if the AC turns on
6. Access AC unit and check to see if all the sensors are connected and working properly
7. If you cannot figure out why the AC unit is not running, order a new unit and replace it

TA23-450-C – Troubleshooting flow chart for the ultraview cab air conditioning system_EN

May 25, 2023May 25, 2023

MRH deadman button not working

Operator complained the deadman button wasn’t releasing.

The bell crank that operates the deadman switch pin broke. The temporary fix was to remove the top of the joystick and button and manually lift the deadman lock pin. When the technician was able to arrive on site a T85 joystick was used in place of the MRH joystick until replacement parts were made. The Deadman contact is different from a T85 stick and so the contact switch needed to be swapped.