The adiabatic temperature change ΔT _ad of a Mn _1.3 Fe _0.7 P _0.5 Si _0.55 Fe ₂ P-type alloy was measured under different magnetic field-sweep rates from 0.93 Ts ⁻¹ to 2870 Ts ⁻¹ . We find a field-sweep-rate independent magnetocaloric effect due to a partial alignment of magnetic moments in the paramagnetic region overlapping with the magnetocaloric effect of the first-order phase transition. Additionally, the first-order phase transition is not completed even in fields up to 20 T leading to a non-saturating behavior of ΔT _ad . Measurements in different pulsed fields reveal that the first-order phase transition cannot follow the fast field changes as previously assumed, resulting in a distinct field-dependent hysteresis in ΔT _ad .