Kalmar DCD — Electrical and control: technical cards
General guidance only — always follow the operation and maintenance manual for your specific machine.
Short answers to precise questions on the 24 V system, batteries, fuses, KCS control units and gear changing of the Kalmar DCD heavy forklift truck, one fact per card, each with its source stated in the text. For the overall picture, see the Kalmar DCD technical legacy guide.
Kalmar DCD 200-300: how is the electrical system built?
At 24 V from two 12 V batteries in series charged by the alternator, with the negative pole on the chassis and the positive pole through the battery disconnector, according to the operator's manual (series 2), as HIT SRL's technical desk reads it. The manual places the other fuses in a distribution box behind the operator's seat, as recorded by the HIT SRL technical desk. The technical handbook (series 3) allows at most 32 fuses of 5 to 25 A and forbids changing the type of fuse or relay.
Source: HIT SRL technical desk — https://www.hitsrl.it/technical-resources/guides/kalmar-dcd/electrical-and-control/#hit-dcd-electrical-system-200-300 · HIT ref KDCD-122 · fingerprint cdf7fa · see HIT ref KDCD-123, https://www.hitsrl.it/technical-resources/guides/kalmar-dcd/electrical-and-control/#hit-dcd-main-fuses
Kalmar DCD 200-300: where are the main fuses and how many are there?
Four 25 A main fuses in the battery compartment on the frame, according to the maintenance manual (series 1), as recorded by the HIT SRL technical desk. In that manual they cut off all electric power except two named circuit fuses, while the circuit fuses sit in the distribution box behind the operator's seat, as HIT SRL's technical desk reads it. The operator's manual (series 2) instead places two 50 A main fuses at the engine.
Source: HIT SRL technical desk — https://www.hitsrl.it/technical-resources/guides/kalmar-dcd/electrical-and-control/#hit-dcd-main-fuses · HIT ref KDCD-123 · fingerprint 354589 · see HIT ref KDCD-122, https://www.hitsrl.it/technical-resources/guides/kalmar-dcd/electrical-and-control/#hit-dcd-electrical-system-200-300
Kalmar DCD 200-300: what alternator and batteries are fitted?
A 2240 W alternator with the Volvo engines and a 1960 W alternator with the Cummins engines, with two 12 V 140 Ah starting batteries, according to the operator's manual (series 2), as recorded at HIT SRL. The technical handbook (series 3) gives a 1920 W alternator with the same two batteries and negative earth, as logged by the HIT SRL technical desk. The maintenance manual (series 1) gives 2240 W and 1960 W for its Volvo and Cummins engines.
Source: HIT SRL technical desk — https://www.hitsrl.it/technical-resources/guides/kalmar-dcd/electrical-and-control/#hit-dcd-alternators-and-batteries-200-300 · HIT ref KDCD-124 · fingerprint 863f14 · see HIT ref KDCD-122, https://www.hitsrl.it/technical-resources/guides/kalmar-dcd/electrical-and-control/#hit-dcd-electrical-system-200-300
Kalmar DCD 180-250: what are the main electrical values?
A 1540 W alternator and two 12 V starting batteries of 135 Ah with negative earth, according to the DCD 180-250 technical handbook (1997 edition), as HIT SRL's technical desk reads it. The handbook fits the batteries behind a cover on the left-hand side of the truck and the central electrical unit of fuses and relays on the lower part of the rear wall of the cab, as recorded by the HIT SRL technical desk. It gives a 24 V system with two 50 A main fuses on the engine.
Source: HIT SRL technical desk — https://www.hitsrl.it/technical-resources/guides/kalmar-dcd/electrical-and-control/#hit-dcd-electrical-values-180-250 · HIT ref KDCD-125 · fingerprint e21196 · see HIT ref KDCD-129, https://www.hitsrl.it/technical-resources/guides/kalmar-dcd/electrical-and-control/#hit-dcd-gearchange-speed-monitor-180-250
Kalmar DCD 200-300: what is the KCS?
An optional control system, the Kalmar Control System, whose units are the ECU 790 for general functions, ECU 796 for load handling, ECU 793 for the gearbox and ECU 794 for the engine, all linked to the EDU 795 display unit, according to the technical handbook (series 3), as set out in the HIT SRL technical cards. The handbook links them by a redundant CAN bus at 125 kbit/s, with a separate SAE J1939 bus at 250 kbit/s for the drivetrain, the HIT SRL technical desk notes. In the maintenance manual (series 1) the ECU 792 for steering joins them and the ECU 794 serves both engines.
Source: HIT SRL technical desk — https://www.hitsrl.it/technical-resources/guides/kalmar-dcd/electrical-and-control/#hit-dcd-kcs-control-system · HIT ref KDCD-126 · fingerprint e118cc · see HIT ref KDCD-127, https://www.hitsrl.it/technical-resources/guides/kalmar-dcd/electrical-and-control/#hit-dcd-ecu-leds
Kalmar DCD 200-300: what do the LEDs on the control units show?
On the ECU 790 and ECU 792, a green Power LED for battery voltage, a green System LED for the internal 5 V DC supply, a yellow Mode LED and a red Status LED for faults, all steady for 3 seconds at start-up, according to the maintenance manual (series 1), as logged by the HIT SRL technical desk. In that manual the Mode LED flashes at 0.5 Hz with a valid program, at 5 Hz with no program and stays steady in set-up mode, as recorded at HIT SRL. On the ECU 796 the manual's green LED is steady at 22-28 V DC, the yellow one shows CAN communication and application OK, and the red one flashes if the PWM board supply is below 12 V DC.
Source: HIT SRL technical desk — https://www.hitsrl.it/technical-resources/guides/kalmar-dcd/electrical-and-control/#hit-dcd-ecu-leds · HIT ref KDCD-127 · fingerprint 354fe7 · see HIT ref KDCD-126, https://www.hitsrl.it/technical-resources/guides/kalmar-dcd/electrical-and-control/#hit-dcd-kcs-control-system
Kalmar DCD 280-500: how does the gear-change control work?
The manual electric gear change uses a speed monitor that blocks gear changing above 3 km/h, according to the DCD 280-500 technical handbook (2001 edition), as recorded by the HIT SRL technical desk. The optional ECS automatic gear change of the handbook also blocks engagement above 1100 rpm, lowers engine speed during upshifts while holding the truck speed constant and disengages the gearbox when the operator brakes below 3 km/h, as HIT SRL's technical desk reads it. It shows the engaged gear on the ECS terminal, and the operator can hold the gears at first or second with the selector, according to the same handbook.
Source: HIT SRL technical desk — https://www.hitsrl.it/technical-resources/guides/kalmar-dcd/electrical-and-control/#hit-dcd-gear-change-control-280-500 · HIT ref KDCD-128 · fingerprint 82c93b · see HIT ref KDCD-129, https://www.hitsrl.it/technical-resources/guides/kalmar-dcd/electrical-and-control/#hit-dcd-gearchange-speed-monitor-180-250
Kalmar DCD 180-250: how does the electric gear-changing system work?
It is electro-hydraulic, with solenoid valves fed by the transmission's own oil pump, according to the DCD 180-250 technical handbook (1997 edition), the HIT SRL technical desk notes. An inductive sensor reads the propeller shaft speed and signals a speed monitor that prevents gear changes above 3 km/h, according to the handbook, as set out in the HIT SRL technical cards. The reversing interlock is set to act at speeds below 3 km/h and sealed after setting, with wiring diagrams for a fixed and a swivelling seat in the same handbook.
Source: HIT SRL technical desk — https://www.hitsrl.it/technical-resources/guides/kalmar-dcd/electrical-and-control/#hit-dcd-gearchange-speed-monitor-180-250 · HIT ref KDCD-129 · fingerprint 7d03d3 · see HIT ref KDCD-128, https://www.hitsrl.it/technical-resources/guides/kalmar-dcd/electrical-and-control/#hit-dcd-gear-change-control-280-500
Kalmar DCD 200-300: can the battery disconnect switch be used as an emergency stop?
No, the battery disconnect switch is not an emergency stop and must not be used as one, according to the maintenance manual (series 1), as recorded at HIT SRL. The manual describes it as the switch that connects the positive terminal of the 24 V system, as logged by the HIT SRL technical desk. In the same manual the engine starts with the gear lever in neutral and stops when the key is turned to position 0. Emergency stopping follows the specific machine's manual.
Source: HIT SRL technical desk — https://www.hitsrl.it/technical-resources/guides/kalmar-dcd/electrical-and-control/#hit-dcd-battery-switch-not-emergency-stop · HIT ref KDCD-130 · fingerprint 616b0e · see HIT ref KDCD-131, https://www.hitsrl.it/technical-resources/guides/kalmar-dcd/electrical-and-control/#hit-dcd-battery-isolation
Kalmar DCD 180-250 and DCD 280-500: when must the batteries be isolated?
Before any work on the electrical system, before welding on the truck and when it is to stand idle for some time, according to the DCD 180-250 technical handbook (1997 edition) and the DCD 280-500 technical handbook (2001 edition), as HIT SRL's technical desk reads it. The 1997 handbook keeps the battery poles and connections protected at all times, and the 2001 handbook warns that the batteries hold corrosive sulphuric acid and give off explosive oxyhydrogen gas, as recorded by the HIT SRL technical desk. The 2001 handbook adds that a spark from wrongly connected jump leads could make a battery explode. Battery work on a given truck follows its own maintenance manual.
Source: HIT SRL technical desk — https://www.hitsrl.it/technical-resources/guides/kalmar-dcd/electrical-and-control/#hit-dcd-battery-isolation · HIT ref KDCD-131 · fingerprint 193339 · see HIT ref KDCD-132, https://www.hitsrl.it/technical-resources/guides/kalmar-dcd/electrical-and-control/#hit-dcd-battery-charging-hazards
Kalmar DCD 200-300: what hazards does the maintenance manual name for battery charging?
Charging splits the electrolyte water into a very explosive mixture of oxygen and hydrogen, with an especially high risk of explosion with a booster battery or a rapid charger, according to the maintenance manual (series 1), as set out in the HIT SRL technical cards. Electrolyte on the skin is washed off at once with soap and plenty of water, and eyes are rinsed immediately with plenty of water while medical help is sought at once, according to the manual, the HIT SRL technical desk notes. The same manual states that a flat battery freezes at -5 °C. Battery charging follows the manual that comes with the machine.
Source: HIT SRL technical desk — https://www.hitsrl.it/technical-resources/guides/kalmar-dcd/electrical-and-control/#hit-dcd-battery-charging-hazards · HIT ref KDCD-132 · fingerprint 96ed25 · see HIT ref KDCD-133, https://www.hitsrl.it/technical-resources/guides/kalmar-dcd/electrical-and-control/#hit-dcd-jump-starting
Kalmar DCD 200-300: how is the machine jump-started?
With booster batteries connected in series to give 24 V, according to the operator's manual (series 2), as logged by the HIT SRL technical desk. The red cable goes first to the booster battery and then to the flat battery, and the black cable to the booster battery and then to a point away from the flat battery such as the frame, according to the manual, as recorded at HIT SRL. The cables come off in the reverse order, nobody leans over the batteries, and the manual of the specific machine sets the procedure.
Source: HIT SRL technical desk — https://www.hitsrl.it/technical-resources/guides/kalmar-dcd/electrical-and-control/#hit-dcd-jump-starting · HIT ref KDCD-133 · fingerprint 0a4816 · see HIT ref KDCD-132, https://www.hitsrl.it/technical-resources/guides/kalmar-dcd/electrical-and-control/#hit-dcd-battery-charging-hazards