Chapter 4 Maintenance 41
ECM3 Series Outdoor Power System User Manual
1. Turn off the AC output MCB of power subrack, and the position is shown in Figure 4-4.
应急风机
风机固定螺钉（共
4
颗）
Fixing screw of fan (4 pcs)
Emergent fan
Figure 4-4 Position of emergent fan
2. Unplug the fan terminal and loosen the fixing screws of the fan, as shown in Figure 4-4.
3. Remove the faulty fan and replace with a new fan, and fix the fan with screws.
4. Restore the connection terminals of the fan.
5. Switch on the AC output MCB of the power subrack.
4.2.2 Replacing Heater
The procedures for replacing the heater of heating unit are as follows:
1. Turn off the AC distribution MCBs and DC power supply in thermal control unit, and unplug the power input
terminals of the heater.
2. Disconnect the power input terminals of the heating unit and loosen the four fixing screws of the heating unit, to
remove the entire heating unit from the cabinet door, as shown in Figure 4-2.
3. Use a cross screwdriver to loosen the nine fixing screws of the heating unit cover, and remove the heating unit
cover, as shown in Figure 4-3.
4. Loosen the eight groups of M4 nuts, flat washers, spring washers (see Figure 4-5) used to fix the heater, and
remove the heater.
M4
螺母、平垫、
弹垫（共
8
组）
加热器
M4 nut, plain washer and
spring washer (total 8 groups)
Heater
Figure 4-5 Position of heater
5. Reverse the preceding steps to install a new heater.
6. Plug the connection terminals, and restore the AC distribution MCBs and DC power supply in thermal control unit.