Toshiba MMY-MAP0804FT7(Z), Service Manual, Page: 257 / 333

– 257 –
11. REPLACING COMPRESSORS
11-1. Compressor Replacement Procedure (Outline)
NO YES
YES
NO
START
Is the outdoor unit the only one in the system?
Recover refrigerant
from the failed unit in
accordance with “10
OUTDOOR UNIT
REFRIGERANT
RECOVERY
METHOD”. Manually open PMV1, 2
and 4 of the failed unit
(by short-circuiting the
pins of CN30 on I/F P.C.
board and turning off the
power switch), and
recover refrigerant using
a refrigerant recovery
device (*1).
Turn off the power switch of the failed outdoor unit.
Dismantle the faulty compressor.
Check the color of the oil in the faulty compressor.
ASTM grade: Is it 4 or above?
(Judge the condition of the oil against color samples,
and decide whether to replace the replace to the
failed compressor only or all the compressors in the
failed outdoor unit.)
Replace both the faulty compressor and the normal
compressor(s).
Measure the amount of oil in the normal compressor(s).
Adjust the amount of oil according to the oil quantity
measurement result(s).
Install the new compressor(s) (*2).
Perform a leakage check of the failed outdoor unit.
Perform vacuum drying in the failed outdoor unit.
Refrigerant charging
END
Measure the amount of oil in the faulty compressor.
Replace the faulty compressor only.
Amount of oil 4300cc 6700cc
MAP0804
∗
, 1004
∗
MAP1204
∗
, 1404
∗
WARNING
In situations such as indoor unit relocation and
repairs, it is not possible to recover all the
refrigerant held by the system in the outdoor units.
It could cause a serious accident, such as blow out
or injury.
Be sure to perform refrigerant recovery using a
refrigerant recovery device.
WARNING
When detaching a pipe by heating with a burner a
welded joint, take care as any oil left in the piping
may burn in a momentary flash of fire when the
weld filler metal melts.
*1 The full-opening of PMV1, 2 and 4 via short-
circuiting of the CN30 pins is automatically
undone after 2 minutes, causing the valves to fully
close. To maintain fully open state, turn off the
power switch of the outdoor unit within 2 minutes.
*2 The SHRM-i (4 series) and the SHRM (2 series)
use different types of compressors.
Be sure to check the service part code.
This flowchart only shows the standard compressor
replacement procedure. Since the situation can differ
site by site, perform the task in accordance with the
following judgment criteria:
(1) New compressors are charged with 1900cc of oil
per unit.
(2) The amount of oil held by an outdoor unit is as
shown below.
(3) When a compressor is dismantled, it usually
contains 800-1400cc oil.
The amount of oil held by an oil separator is
usually 0-1000cc for MAP0804
∗
, MAP1004
∗
and
0-1500cc for MAP1204 ∗ and MAP1404 ∗ .
AMP Air Conditioning www.ampair.co.uk | sales@ampair.co.uk